LG CF21D70. When you turn on the TV, after 2-3 seconds it goes into standby mode. The reason is the breakdown of the diode 2N4148 (150V) according to the D408 scheme. Already 3 cases in 3 months.

GOLDSTAR CKT-4905 The TV does not turn on. At the output, instead of 115 volts, 40. Moreover, the voltage on the diode is normal, and after relay 40, the power supply works without additional overload sounds. The 115 volt diode gets very hot. When checking the secondary circuits, no suspicious parts are found. The capacitor C8075 160V \ 33Mkf turned out to be faulty. Checking the capacitance on the device showed the presence instead of 33 uF of only 0.23 uF, the leakage was 50 ohms. The defect is very common. I replaced the broken TDKS in TV LG: 154-375F, after which I observe a strange effect: service information (program number, menu lines) twitch vertically 2-3 cm, the main image is normal, if you reduce the SCREEN voltage on the TDKS twitch stops, the brightness of the scene is also affected. It turned out that the secondary voltage from the TDKS to the personnel supply was too high - 29v instead of 24v. I put 3 diodes in series in this circuit and that's it.

TV LG CF-20D30 when you turn on the power button, the LED on the front panel blinks once and nothing more - the PSU has not started, there are no secondary output voltages. The electrolyte in the STRS5707 harness turned out to be the culprit (it stands between the STRS radiator plates, C = 4.7 microfarads * 50V), which lost its capacitance to 1 microfarad.

Gold Star (LG) 21D16. The guys have overdone something in this model with stereo sound on an additional board and TDA2009A. In a number of boxes, after six months or a year of work, a problem appears in the form of hoarse (farting) and faint sound. The most optimal solution to the problem, without replacing the microcircuit, turned out to be a 2-3 MΩ resistor between the input of the first and second TDA channels and + 12V.

Goldstar CB-28C22X. Narrow horizontal stripe. Broken 2-zener diode 24v, charred R304. After replacing the zener diodes, the strip remained, R304 is heated. Replaced out. k. frame. dev., TDA8350Q- the resistor stopped heating, but the band is still the same. (The desired circuit is at hand as always). After analyzing the circuit, I found that 2 power supplies come per ms: for 4 and 8 legs. On the 4th output, D702 is broken, FR702 is open. After the replacement, the TV worked. (On the Internet, the dock on the TDA8350Q can be found on the industrial electronics website.)

TV Goldstar CF-21E60B. An external sign of a malfunction - h / s a ​​few minutes after turning on - no image (dark screen) and sound in the presence of a raster, no reaction to commands from the remote control (controlled from the TV panel), and later - a breakdown in video synchronization and spontaneous entry into the duty room mode, and after a while the functions are restored, and everything repeats. The malfunction is in the LG8534-13A processor, part of its circuit is analog adjustments, switching on and off, the remote control command decoder fails during heating. Treatment - in secret ¦125, without soldering, applying a layer of CPT and applying a copper plate on top of the size of the body, roasted with a 65-watt soldering iron until the solder on the plate stopped solidifying (8-15 seconds). Second successful recovery.

LG CF-21K49 based on the MC994A chassis. The symptom does not turn on or has a narrow vertical bar on the screen. The capacitor C411 334/200V is most likely to be replaced.

LG CF-20D30 (Chassis: MC64B). No reception on the upper meter subband. The error came to light rather unexpectedly. The main one (on which there was a call) was: the network power button (white, expensive 150 rubles) deteriorated. After replacing the switch, it turned out that there was no turn-on voltage of the HV subrange (instead of 12V, only about 5V). Switching voltages are supplied through transistors, a quick check of which showed that everything is OK. Everything was rounded off, as it were, on a tuner (an ordinary eight-legged one). But I have never encountered such a defect. Doubts turned out to be true. After soldering the little things around the output of the HB tuner, it turned out that the Q181 2SA1266 transistor (p-n-p 50V 0.15A) sounds like a normal one at Ohms, and at kOhms it has R (b-e) arr. = 150 kOhm. He then planted 12V at the output of the tuner.

TV LG-CF21D79, there is no oversaturated B/W color image, as if there is no luminance signal. Replacing the TB1238BN video processor did nothing. The SECAM TA1275AZ chip turned out to be faulty.

TV LG20 on MS-84A chassis. The defect may not be common (I met it once), but it seemed interesting to me. Slowly responds to commands, poorly configured and does not remember the settings. The service turned out to have all the settings at zero, but when you enter the proper initialization modes and exit the service, everything repeats. Replacing the memory did nothing. It turned out that two of the eight resistances in the ceramic assembly showed ~ 2.4kΩ instead of 4.7kΩ.

Problem with LG Chassis MC-019A. TV does not come out of standby mode, if you measure the power line - about 70 volts. First of all, look at C820 220 MF 160 B, most often one of the capacitance terminals is broken, the terminals are formed at a very sharp angle.

LG CF-21D70 (Chassis: MC-64A). When turned on, it goes into standby mode, and then goes out completely. The analysis showed that when applying mains voltage, output voltage+V smoothly rises to more than +160V (norm +125V), and then works internal protection and the generation of BP is disrupted. Analyzing revealed a defective electrolyte C824 4.7 μF 50V (leakage, drying out or increase in internal resistance at HF), installed between 4 pins. optocouplers IC801 and 7 pins. STRS5707. What pleases is the timely internal protection, which did not allow the murderous + V = 160-180 V to roam.

TV Gold Star CF21E20 chassis MC-41A Lost sound. Quite quickly I found that the volume control signal is almost at zero, you unsolder the output of the control processor GS8434-16 (3pin) - it yells to the fullest, there is no sound in AV mode either, it would seem everything is clear, it is necessary to change the percentage - not such a rarity. .. But after the replacement, the situation did not change, flashing the USB flash drive to a known good one also did not bring results. I had to start thinking .... I take out the antenna - after 10 minutes the TV turns off - well, this is how it should be. I leave it with a signal from the air - after the same 10 minutes it turns off - clearly, there is no SOS signal (it is designated here as ID- 17pin of the processor) - constantly high level. Unfortunately, a stereotype of thinking worked here - I apply low to this input, but the situation does not change, and in the video input mode there is also no sound ... In many television processors, the SOS signal is integrated and evaluated by level, respectively, and it is easy to track it When the station signal fails, the level changes dramatically. Here the signal is pulsed - SSC pulses are used. Transistor Q06 - ID "drip" signal conditioner transition K-B, there were no pulses at the ID input. AT Samsung TVs when the “sweet couple” failed and the protection was broken, R2M pierced the TDKS- in the upper part, a gap of about 5 mm formed near the exit of the high-voltage wire and a spark struck from it into the core. The advice on restoring the TDKS helped a lot here - I drill a couple of mm deep into the crack with a large drill and fill it with white auto-sealant, after 3 hours you can turn it on. Thus, 2 transformers per week.

On TV LG-21D70X when you turn it on, switch programs, information about the settings is not saved. After pressing the network button, the TV turns on in LINESVC mode, from which it switches to normal mode after pressing the TV / AV remote control button. After replacing the 24C02 memory and turning it on, the TV switched back to LINESVC mode, then after pressing the TV / AV button on the remote control, the TV switched to normal mode with the restoration of the settings saving functions. No additional steps were required to "firmware" the memory chip.

GoldStar and LG TVs before 2000. Problems with the tuner, does not remember the settings, etc. Sounds like a tuner failure. Solder ground contacts in the tuner.

TV Goldstar CF20A80Y. When turned on, you can hear the sweep operation, but there is no sound and no raster. The malfunction lies in m / s D402 (7809) manufactured by KIA. It stands together with D401 (7812) on the same heat sink, not far from the TDKS.

Gold Star CF-29C44 When turned on, the TV goes into protection. Replace on the PIP KRENKO 78L08 board with item number IC7P. Almost all malfunctions in these models are associated with this KPENK.

GoldStar CF-21D60B. No sound. I got the 2nd TV with such damage. The sound control output on the 3rd leg of the LG8434-03C processor is faulty. Our processor costs ~ 800r. If the client is satisfied with the sound, you can start to adjust the contrast of this processor. Set the contrast to the optimum of your choice. The only inconvenience is the sound adjustment through the menu.

LG CF-20D60. It does not turn on, when measured in the power supply, it starts up. It is necessary to replace the capacitance 4.7mFx50V (located in the alignment of the radiator 5707).

LG CF-21D70 Spontaneous transition to standby mode. On the different channels differently, on some after 5 minutes on others after 10 minutes. Try to replace the electrolyte of position C408 with a nominal value of 160V1mF, it dried up to 0, in addition, it was also leaking.

LG CT-29K37E. When you turn on the relaxation of the power supply, it enters the operating mode after 5-6 attempts to turn it on and off. It is necessary to replace C808 (100.0x35V) in the power supply, which is assembled on the STR-F6656 chip.

LG CF21D33 - does not turn on. +185v = short circuit to ground - change TDA6107Q (by the way, there was a recently defective batch of these ic in Promelectronics with the number 3 in the lower right corner)

Quietly beeps broken D5072. change and get a heartbreaking whistle !!! (What did they fight for?). It turned out that Korean saboteurs smeared the inside of the OS with a new "super lock glue". But nothing, we are not proud people - we remove the OS, we wash the place of the short circuit. with the purest Russian alcohol, we move the coils apart, put in electrical tape - and everything is in place.

GoldStar SF-14A90B a few seconds after turning on the screen became bright white. The KIA7805 (5 V) stabilizer, which is powered by the processor, turned out to be faulty; during these few seconds, it raised the voltage at its output to 7 volts.

Supra CTV1485 MC-41A chassis, aka Goldstar GF-14/20/21A80 MC-41A/B. There is no blue color in SEKAM, everything is OK in PAL. SEKAM contour blue B-Y core L504, does not react to rotation. Do not rush to change the TA8750AN chip, swap the L504 and L502 circuits connected via capacitors to pins 35 and 29 of the TA8750AN. In my case, after rearranging the contours in some places, everything worked, obviously, the soldering of the legs (inside) of the contour affected, after which a slight adjustment of the contours is required.

LG CF-21F89 Chassis MC994A Symptom - turns on for a few seconds then goes into st-by. During the turn-on time, the line transistor has time to heat up. Closed the line coil in the OS.

LG CF20F30. The fuse is on. The diode bridge and the IC802 STR5707 chip are broken. The bridge was soldered from KD105s, I bit off 1 and 3 pins in the microcircuit, turned it on, there are start pulses on the 4th leg. I hung a KT872A transistor (k-1n, b-3n, e-2n) on the wires, turned it on and it works. Tr-r put on a suitable radiator.

LG CF-21D70 Chassis MC64A. Spontaneously chaotically goes to the "duty room". Regardless of the operating time, heating or cooling. Replacing processors and memory did not give results. As a result of a long search, the defect was nevertheless revealed - C408 1mkfX160v dried up in the Q401 circuit (the end of the line). In the same TV, B.P. does not start. - drying of S824 4.7mkfH50v in the optocoupler circuit.

GOLDSTAR assembled on TDA3562A - Dark screen. Cause C -10mF/250V, filter +180V

GOLDSTAR CKT9905 - Pale image, +112V is normal, and the supply voltage of video amplifiers +180V is too high to +270V - Faulty C806 (47mF/160V)

GOLDSTAR CKT9582 - White raster with reverse beam path - leakage of transistor Q906 (BF421).

LG CF-20K51KE Breakdown of the line transistor Q402 D5702 on the case, with burnout. After replacing - a new one flew out in a second. Replaced Q402 with BU2520DX, they are more reliable. Careful check of a binding - did not bring result. Disconnected one output of the OS line coils and briefly turned on the TV. The screen lit up with a stripe. Turned on briefly with the OS. The screen lit up with a compressed screen. The transistor is intact. Changed OS. The result is positive. In a broken OS - no defects were found.

GOLDSTAR 21E60. Does not turn on. Broken line transistor, TDKS and interturn circuit in the deflecting system.

LG CF-14G20R. Weak sensitivity. Interference and noise in the image. The IF filter of the K6265K radio channel turned out to be to blame for this disgrace.

GOLDSTAR 21E40. No high voltage. PSU works, there is sound. The amplitude of the line-scan trigger pulses based on the pre-output transistor СР is small. On the 37th leg of the video processor, the voltage is 0.4 V. Reduced resistor R524 from 3.9 kΩ to 2.4 kΩ. The voltage increased to 0.57 V and its amplitude became sufficient to open the transistor.

ELEKTA CTR-1495EMK, GOLDSTAR CKT-4442B, CKT-9322B. Chassis PC-05X2. (There is no image (may flash vaguely), the screen is gray!, There is sound. One of the reasons for this defect is the failure of the video signal switch, the microcircuit (GL3820, aka TEA2014A) is located on the video input board.

ELEKTA CTR-1495EMK, GOLDSTAR CKT-4442B, CKT-9322B. Chassis PC-05X2. Defect - there is no color image in the SECAM system. Enough common cause- tuning capacitor SVC1 (stands next to the quartz resonator) in the SECAM-PAL transcoder circuit.

ELEKTA CTR-1495EMK, GOLDSTAR CKT-4442B, CKT-9322B. Chassis PC-05X2. The TV does not tune or the setting is lost. It may be enough just to solder and solder the tuner. At least there was a defect.

ELEKTA CTR-1495EMK, GOLDSTAR CKT-4442B, CKT-9322B. Chassis PC-05X2. The TV does not turn on, there is no indication. The standby power supply transformer often fails. TP-8-3, or similar, is quite suitable for powering a 12 volt source. However, there was a case when the power supply of the standby mode was, it turned out - an annular break of KRENK IC2 (7805) :)

ELEKTA CTR-1495EMK, GOLDSTAR CKT-4442B, CKT-9322B. Chassis PC-05X2. There is no image, the screen is dark green, "LOHs" are visible, there is sound. The reason is the drying of the air conditioner in the power circuit of the video amplifiers (the voltage dropped right up to ... 119V, instead of 180-190 volts! The screen can be completely dark (the power supply of the video amplifiers in that case was about 160! Volts).

ELEKTA CTR-1495EMK, GOLDSTAR CKT-4442B, CKT-9322B. Chassis PC-05X2. The screen is bright white (or gray), brightness, and other adjustments are practically impossible, the image only slips when you turn on the TV. Most likely, this defect is a feature of color blocks with the ABB scheme. The cause of the malfunction is most often the video processor or the A1015 transistor on the kinescope board.

GOLDSTAR CF-20E20B When you turn on the TV, there is no raster and sound, high voltage there is. Fault: stabilizer IC402 (KIA7809)

LG CF-20F30 Chassis MS-64A automatically turns off in standby mode from 10 minutes to an hour. The entire board in the literal sense of the word "plowed up on elephants and camels", only the percentage of management was not touched due to its high cost. The reason for the disconnection of the LG8634-16C processor on the 20th pin, through the ABNORMAL protection bus, is the loss of capacitance of the capacitor C408 1uF * 160v in the TMC primary power circuit.

Goldstar LG CF-14/20/21A80V Doesn't come out of standby mode. When a command to turn on is given, the voltage tries to rise and immediately drops to the value of the standby mode. Replace SE120N. Sometimes the PSU won't start. Solder the trigger circuits.

LG CF-21F3. Immediately after switching on, it goes into standby mode. No vsync on cpu. Fault-open R15 4.7k

LG, CF-21F39, 2 years old. When switching from standby to working mode, a burning smell appears and the TV goes back to standby. Open the lid, turn it on. Smoke is coming from the left side of the OS. We remove the deflecting one. On the inside, a breakdown is detected between adjacent windings. At the junction separated by a plastic rib of the OS case. The insulation burned on 3-4 wires on each side. It is necessary to carefully part, remove the "coals", lay the wires in the cambric and fill with sealant. It is interesting that after 1.5 months the client complains that the same thing happens again. The smell appeared and turned off by itself. I remove the OS and find the same breakdown only now on the right. Now, this is a topic for thought. As it is written on the cover of the TV: made in Ukraine from LG components. On the deflector we read: Planzhuan OPC 29-90-54. Made in China. But there is one more thing. Rubber wedges, which are placed under the OS, (of which there are usually 3 pieces and stand at an angle of 120 degrees) here are 4 pieces. Two vertically and two horizontally - exactly under the breakdown site. It seems that the rubber is not conductive, but it may be that heat was poorly removed, etc. Or the Chinese are chasing marriage. Life will show.

LG CF-21D33E, chassis MC-84A similar breakdown of the Pianzhuan QPC 29-90-54 deflection system. Collected in Russia. When trying to replace the OS, large dilutions from the top and bottom. The breakdown occurs in two places where the turns from the two coils are closest, located along the horizontal axis. At these points, the turns are additionally fixed with a brown compound. Through it, then the closure hits. After removing the "coals" and the compound from the opposite side, wiring the turns, and pouring hot glue, the OS started working. The rendezvous is at its best.

I confirm this defect. Two TVs a week. OS Pianzhuan QPC 29-90-54. TV assembled in Russia. We could not find another OS. Correction is not output. Restored old OSes!

GoldStar CF-14A74Y Chassis MC41A after a thunderstorm, the STR-S6707 and the optocoupler TPL721 took off. After replacement and when checking b / p. to an external load of 60W, it worked fine. When you turn on the TV, the 112V channel is set to 85 and 90V, i.e. with a frequency of approximately 3-6 seconds, voltage jumps occur from 85 to 90 and back. At 85V the screen is compressed horizontally and White screen, and at 90V the operation of the TV is normal, but there are buzzing changes in the speakers and the line transistor is heating up. The SE110 chip turned out to be faulty (it turned out that the reason was in it after connecting an external load of 150W to the power supply unit).

GoldStar CF-21E60B Image distortion, no brightness signal, color disturbance. Replacing the TA8750 and the TA8690 video processor, soldering the tuner did not give anything. Voltage 12V and 9V is normal. Faulty IC201 LA7222 - video input switch

LG (I don't remember the model) with a 24C02 memory chip. If, after turning on, adjust the volume with the buttons on the front panel, then it is adjusted as follows: 0-50-100-mute, if you turn it off in standby mode and turn it on, it fills with white, protection is triggered. Replacing the memory chip fixed all the problems.

Defect - no frame scanning in devices: LG CF-20E60K chassis MS-64A. Open resistor R311 2.2 ohm.

Goldstar CF-21D10B There is no picture or sound, no noise, the screen is dark. Almost like in secrets No. 487 and No. 949, but - service information is displayed (menu, controls, channel number, etc.) string transformer.

LG CF-20K50E chassis MC-84A. It stands in the duty room and does not turn on either from the remote control or from the TV panel. It turned out one resistance 4.7k in the ceramic assembly near the control processor in the cliff. I hung a similar resistor on the other side of the board: the box worked, but the raster was compressed vertically and shifted to the left. I didn’t go into the service, I changed the memory, the raster became normal.

GoldStar CF-21D60. The raster glows faintly, there is no image, there is sound. The amplitude of the V-Syng pulse at pin 2 of the processor is small ~1V. The reason is a broken zener diode ZD01 (5V1).

Goldstar CK-20A80. No picture, sound, OSD, video amplifiers are locked. Sometimes he does not even want to turn on from the duty room. Faulty m / s PROM (** 24C04). We solder clean and everything.

LG CF-20F60. Received from another workshop with a diagnosis - the processor is faulty. The device behaved in a rather original way: at first it started working, after five minutes it hung up and didn’t want to work anymore during the day. After resting for about twelve hours, he again began to work, hung up, and everything was repeated anew. Three resistors in the AR02 assembly turned out to be faulty, two of them were connected to the I2C bus pins of the processor, and the resistor values ​​changed not upwards, as is most often the case, but downwards. Instead of the prescribed 4.7 kOhm, it became 2:3 kOhm. For reliability, I had to replace the entire assembly with ordinary resistors.

GOLDSTAR CF-25C36X. Defect - no image and sound, weak noises on the screen. Suspicion first fell on the TDA9808 (radio channel), but the reason was IC182 KIA7805 (5-volt power TDA9808) - instead of 5 volts, it gave out 3.

GOLD STAR CF-29C32J Does not turn on (after a thunderstorm). Broken tr-r Q301 2SB988Y replacement with 2SB1294. TV did not turn on, there is no start of the primary circuit. Open R811 470k earned after the replacement.

LG, MS-64A chassis, PSU on STR-S5707 assembly. BP does not start. Leakage in C820 is 220 uF, which is on the 9th leg of the assembly. The capacity showed normal and did not detect itself when dialing with a digital tester. The voltage on this leg was 7.2 V (instead of 7.9 V, as it turned out).

LG modelCF-21K50E. Defect - there is sound, there is no image, the screen is dark. At the autopsy, it turned out that there was heat, voltage on the cathodes too. As the accelerating voltage was increased, a bright narrow horizontal band appeared. The LA7830 frame chip and the 1 ohm resistor for powering this chip turned out to be faulty. The microcircuit flew out due to the increased voltage from the power supply (145 volts). The reason is that the electrolytes in the strapping of the power supply chip (STR-S5707) have dried up. After replacing the electrolytes, the PSU began to give out 115 volts.

Goldstar CF-20A80V. The power supply does not start. Before the breakdown, the TV did not start well and turned off on its own. Soldering an annular crack in the output of TPI did not help. On 9k STRS6707 supply voltage = 0. (start circuit). It turned out to be a leak 9 input microcircuit.

GOLD STAR CF-20D60B. There is no color in PAL, although the screen displays the inscription: PAL AUTO SYSTEM. At the output 40 m.s. IC501 TA8690 instead of 4 volts only 2.6. Reason: broken output 33 (SECAM-ID) m.s. IC01 GS8334-16A. It was not necessary to change the percent - it was enough to disconnect the defective output from the circuit.

GOLD STAR CF-20D60B. There is no color in PAL and the inscription on the screen: SECAM AUTO SYSTEM. On the output 40 m.s. IC501 TA8690 in PAL voltage 0.78 V. Faulty TA8690.

GOLD STAR CF-20E20B. Another addition to secret 509. SECAM is dominated by red. Malfunction of the capacitor built into the circuit L502 E16A (R - Y). The defective one had to be broken out and replaced with an external one by 100 pF with a slight adjustment of the circuit.

GoldStar CF-21D70R spontaneously goes into standby mode at different intervals, the protection is triggered along the "ABNORMAL" circuit. Defect detected - dry capacitor C408 1.0 x 160 V.

LG-CF-20D70K Returning to secret 415. The degradation of the C824 capacitor in the PSU (4.7 * 50 V) initially leads to difficulties with turning on the TV, but our people are stubborn. Repeated on-off TV include. And in the end it will all end with a breakdown of the power STR-S-5707. This malfunction becomes typical for LG, along with the protection operation due to a malfunction of the 1.0 * 160V capacitor in the preliminary row cascade.

GoldStar CUT9322 chassis PC-05X2 (with a "flat kinescope" in the form of removable glass). Fills with milk, the image is not visible. Replacement for TDA3562A. All the same, the effect remained, although a weak image in the negative began to break through. When you touch the probe to the 8 pin TDA3562A, a normal image appears. Conclusion - the constant drops through the capacitance C514 0.22mF x 50v. The replacement helped, but not for long. The next time you turned it on, the effect was repeated. Enumeration of containers of different quality did not give anything. New conclusion - for TDA3562A microcircuits recent years release, the input impedance at the input Y (8 pin) has been changed. I "planted" this input with a 1.5 mΩ resistor. Everything works great. An additional check of the previously soldered TDA3562A confirmed that it was killed, just at the Y input. A rare coincidence of 2 simple defects leading to pathological consequences, which some masters call a "drum".

GOLDSTAR(LG) CF-14E20B chassis MC-41B . Red lights up (DR indicator), does not respond to buttons, + B = 43V. The reason is X01 (for some reason it was 3.6MHz). According to the 4 MHz scheme, because it didn’t turn out - I put 4.43.

GOLDSTAR (PC04A) 1). C807 replacement does not turn on in the operating mode 2). Chassis MC41V is not sound adjustable, ROM replacement programs are not configured. 3). No sound replacement Q06 adjustment L508. four). No setting of the first range setting L508, 507. 5). The frequency of replacing the m-controller goes away. 6). No Y-signal replacement for LA7222. 7). Understated voltage replacement ZD811 to 7.5V.

GOLDSTAR CF-21E20B and other MC-41B. With warming up, it turns itself off, the DR indicator may blink. You can turn it on only after a while. If at first you don’t discharge the filter and touch the 5th leg of the T802 (there is an annular crack), then you can burn the STRS6707. One device “blew” just when removing the board - while putting it on the table (before that, the TV worked - but waited for the self-shutdown ...). You can start after replacing the STRS6707 only through a lamp of at least 300W (weaker ones flash due to the rapidly growing current consumption after a few seconds).

GOLDSTAR CF-21C22X MC-46A. Burned out when turned on. The DR indicator shines, when turned on, it goes out. For a moment, high and all other voltages appear (not reaching the norm), and then they fall. When TESTING the horizontal output stage with a reduced + V = + 15V - the pulses are without distortion, they may be slightly underestimated, the current is normal. BP no doubt. I would suffer for a long time. But I hung up another OS and -wonder-TV turned on with a narrow chaotic raster. There was a burning smell here. Only a long thorough inspection of almost ALL parts of the SR helped. The culprit turned out to be C401 434n \ 200V. It made its way under voltage and lost part of the capacitance. It was cracked, but it was invisible on the board. I think it would help to test not underestimated + V = + 15V, but a gradual increase in + V to the nominal value. But there was no source and it would be necessary to take measures to limit the current - so as not to burn the test generator itself.

Goldstar on the TA8690 video processor does not configure channels. On those that were tuned, the tuning went away. The AFT circuit did not work on the TA8690 processor after replacing the processor, it returned to normal

GOLDSTAR CKT9905 Fault: after turning on after 5-10 minutes, the TV turns off, while the indicator board goes out. After analysis, the suspicion fell on the on-off relay for the output stage. When the jumper closed the working contacts of the relay, the TV worked normally. After replacing the relay, the TV worked again.

LG CF-20F89. Chassis MC994A. Fault: does not turn on. Power supply on STRF-6707A (not to be confused with STRS-6707). Basically, no<подводных камней>. The chip itself is to blame. But a careful dialing of its conclusions with an ohmmeter did not reveal any differences from the correct one. The board has been removed from the TV. After replacing the microcircuit, the PSU started up, but when switching from standby to operating mode after five seconds. went back to standby. Not immediately, but I guessed to connect a deflector. It turned out that without it, TV does not come out of<дежурки>. It's still nothing. On some instances of Funai, without a deflector connected, a horizontal transistor was knocked out.

LG CF-21S10E There is no frame split, we change the TDA8351 frame chip. We get an image compressed from the bottom to half the screen, we change the TDA 8842 video processor, the image is normal, but do not rejoice, everything can happen again, and TDKS 6174Z-8005A is to blame for this disgrace. Breaks through it at times.

LG CF14E40 no setting replace -TDA8362-5

Goldstar on TDA4601 When you turn on the TV, the Q801 BU508D immediately fails. On TV on the bulbs there is no start, but generation is heard in the TPI. The power supply for 9 n TDA4601 is underestimated, on the basis of BU 508 there are irregularly shaped ripples with interruptions (i.e. Rectangular normal-shaped pulses are absent) Replace C 801 10X16V. In case of failure of the output TR, it is MANDATORY to check R 270 Kom (with the number of TR through the TPI winding on the 4-leg 4601). No start, but sometimes it can turn on, check 12v (power 4601, 9-leg - should be 12v to start)

Goldstar on TDA4601 periodically outputs a line transistor (42-cm kinescope), the B + supply is 140v and is adjusted upwards. Check by soldering the resistance R805 coming from the 3-pin TDA4601 on the B + regulator (should be from 6k2 to 12k) in this device increased to 16k.

Goldstar CBS-6081 A very bright raster glow, it is not possible to reduce the brightness control and Screen on the TDKS, by replacing the check BF421 on the kinescope board.

Goldstar CF-20D60B, Chassis MC-41B When powered on<цыкает>PSU on STR-S6707 and does not start. Synchronized with<цыканием>The PSU flashes the LED on the front panel of the TV. Faulty ZD811 6.8v zener diode in KTD2092 base.

LG - CF-20D73 (chassis MC-84A). Apparatus after a thunderstorm. When the TV was brought to me, the processor reset chip (KA7542) was soldered, the stabilizer 7805 was soldered, SE115 was soldered in the PSU, the jumper to power the video amplifier (TDA6107Q) was soldered, and the line transistor (D5702) was soldered. I loaded the BP light bulb - it works (put 115 at the output). By the way, when you turn on another light bulb, instead of a fuse, it starts up, then a lamp, which instead of a fuse smoothly glows and the PSU is cut off. And without it everything is OK. I soldered the power jumper to the video amplifier, put a KREN-ku, a line transistor for testing (BU208), cut the line scan through the lamp - it caught fire - a short circuit in the line. Disconnected the video amplifier - no short circuit. It turned out to be a breakdown in the power supply of the m / s video amplifier (6 ohms). The processor (LG-8838-07D CXP86441) also turned out to be dead (breakdown on the Reset 18 Ohm leg). The LED and the diode in series with the LED also burned out. I put the LED in a suitable size, the diode - KD521. I replaced the processor, video amplifier, put a line transistor D5702, a reset chip. The TV started up, but instead of the image - a white (with a pinkish tint) screen filled with reverse lines. There is an indication on the screen. Replaced the video processor (TDA8842). An image appeared, but filled with white, and with VOCs. Decreased accelerating - the image is normal (low frequency). Does not remember settings - memory is faulty (24C04). No channel reception - tuner is faulty (TV8PSB02D 911A290E). Inside the tuner, I found two burnt tracks. Soldered the jumpers. There was a bad reception only on the 1st band. Replaced tuner with 6700VPF016A. The remote control does not work - the IR receiver is faulty. I installed the IR receiver and the reset chip from the VCR - they work fine. I eliminated a small pink spot on a blue background in the center of the screen by twisting the magnets on the neck of the kinescope. And lightning hit the antenna - the mass track from the tuner to the arrester with network wires burned out, and another track, near the tuner. In the service, I adjusted the AGC, geometry, did not touch the white balance. Entering the service - press the OK button on the TV and on the remote control simultaneously. To switch the menu in the service, press the yellow button on the remote control. Since there was none on my native remote control, I used the Chinese universal remote control.

LG CF-21D70 (Chassis MS-64A) - in dezh. mode is turned on. When switching to operating mode, there is a very loud and spectacular "shooting" at the TDKS. Sparks fly in all directions. TDKS type 6174Z-8004B is faulty. Its cost is $18-22. On the circuit diagram chassis MS-64A is indicated for a diagonal of 21 "type TDKS 154-375F, the cost of which is $ 8.5. I installed 154-375F without any structural and fundamental alterations. The TV worked. The geometry is normal. I set up SCREEN and FOCUS and that's it. But there is a drawback - the screen is rather blue with blue reverse lines.As a result of the shooting of the horizontal transformer, Q514, Q513 and Q512 (2SA1266Y) in the video amplifier failed.(Instead of 6174Z-8004B in another TV LG CF-21D70 was 154-375E. Sellers also offer analogues 154-194D ($ 10) and HR7906.)

LG CF-21D70 (chassis MC-64A) - When you press the "Network" button, the dej indicator. mode lights up for 2-3 seconds and goes out. The voltages from the PSU when the "Network" button is pressed have nominal values ​​​​for 1 second, then they gradually decrease to 0V for 1-2 seconds. "Network" should turn on in standby mode). The "Network" button is faulty, which supplies power to the TV only while you press it with your hand. The owner of the TV said that the TV was almost always in dezh. mode, i.e. the network button was rarely used.

GOLDSTAR CF-21E20B MS-41 chassis. The credits, which usually run at the bottom of the frame, are doubled so that it is impossible to read them, the picture itself is of normal quality. I connect the test signal generator, turn on the grid via the video input, everything is fine, and the high frequency through the antenna socket clearly shows a strong repetition of vertical lines, it is clear that the malfunction lies in the radio channel. In the end, the malfunction was localized in the K2559 surfactant filter, replaced by K2550.

Goldstar CF-20F60. The TV immediately turns on in the operating mode, bypassing the standby mode. PSU voltage too high. Faulty optocoupler IC801.

Goldstar CF-21C22X Chassis MC46A The power supply is assembled on STRS6707. In the operating mode, the TV works without remarks, but when the TV is switched to St-by mode, clicks are heard from the speakers, the frequency and volume of the clicks can change, then after some time the TDKS starts to squeak in time with the sound, that is, it tries to start. The LED glows normally. The capacitor in the PSU is faulty, 10 microfarads per 100 volts in the secondary circuit, on the control of the optocoupler.

LG KF-21P10 When you turn on the white screen across the entire screen, the beam reverses, the TDA6108 and the zener diode on the 5th leg (IK) 7V5 are faulty.

LG CF-21F30K chassis MC 019A Power supply does not start: replacement of the TT2140 line transistor with 2SD2499 and TDKS 6174Z-6040C (there is a marriage of TDKS-s manufactured on 09-10.2003).

Goldstar CF-14/20/21A80Y. Fault: The buttons on the TV panel do not work correctly. The volume is adjustable in jumps. After replacing the memory chip with a clean one, it worked fine. The programmer reads the memory normally, but gives an error when trying to write. When installing a new memory chip, with firmware from a faulty chip, the panel buttons stop working again. But the old firmware is not required.

Goldstar CF-14/20/21A80Y. Fault: in SECAM - the predominance of red, in PAL the norm. Break out the capacitor built into the L502 circuit, hang 100 pF. In my case, it did not even require contour adjustment.

GOLDSTAR CF-20E20B (chassis MC-41B). Fault: 30 minutes after turning on the TV, the sound disappears. With the back cover removed, the TV can operate normally indefinitely. The GS8434-16A processor recognizes whether there is a telecentre signal by the sync pulses arriving at pin 17 (ID) from pin 21 of the TA8690AN chip. In the absence of this signal, the sound is muted, the level corresponding to the minimum volume is set at the output of the processor's sound control. The transistor Q06 was faulty (type KT315, it was this transistor that was installed during the previous repair) in the circuit for passing these clock pulses. Those who repaired Soviet TVs in large quantities know this feature of the KT315.

LG-CF 20F39 Fault: vertical line. Capacitance break 0.364 microfarads at 400v in the line. Capacitor Manufacturer - WOO YANG

LG-CF14/20/21G20/D70/E60 on MC-64A chassis. Fault: the power supply is turned off. At first glance, all the details are intact, replacing the ic802 chip and the Q810 C3198Y power stabilizer transistor with a zener diode in the base did not give anything. Upon careful analysis, a capacitor with an underestimated capacitance C824 4.7x50v was found. After replacing the capacitor, the unit starts up. By the way, in earlier releases of these models there was a 220.0x5v capacitor, there were no problems.

LG CT-20T30KE Fault: After a while, it starts losing 1 channel or all at once. Can twitch vertical size. May go on standby. May be out of control. The sound disappears. Horizontal scanning disappears for a short time, etc. Replacing the memory (you can put a clean one) and quartz - did not give a result. Replacing the processor TDA9381PS\N2\3/0701. When installing processors with other firmware, the TV does not exit standby mode, while changing the firmware in the memory chip, as it pleases.

LG CT-20T30KE Fault: No PAL color. Replacing quartz 12.000 MHz. Quartz, even new, may not meet the tolerance.

Goldstar CF-14/20/21/E20B (MC-41B). Fault: in SECAM it turns red, sometimes it works fine. Output Capacitor. 26 transcoder AN5633 check by replacement.

LG CT-20T30KE. Replacing the processor TDA9381PS/N2/3/0701(OICTMPH007B) with TDA9381PS/N2/3I0792(OICTMPH010A). Everything is okay. Only the raster is slightly shifted vertically down. I had to look for an entrance to the service. 2 OK buttons on the remote control and TV pressed for 10 seconds. led not to the entrance to the service, but to the inclusion of the self-test mode, after which the TV went out, but did not enter the standby mode

LG, chassis MC-41B. The MV works fine, the tuning goes to the UHF. Setting up the APCG circuit did nothing. When measuring, it was noticed that the TU on the tuner in the UHF range does not change smoothly during tuning, but "jumps". The defect is in the tuner.

GoldStar (LG) 21D16CF, 20A80Y low saturation PAL, Secam norm, GS8334-09C microcontroller replacement

Goldstar GF20D60B PSU does not start (STRS 6707), LED lights up for a second and goes out, MC-1V chassis ZD811 zener diode breakdown

LG CT-21Q42KEX chassis MC-019A The power supply does not start, the F801 fuse burns out, upon inspection it found a burnt diode bridge DB801 D2SB and a capacitor C801 1000p 1kV after replacing the failed parts, the TV started working.

GoldStar CF-21A80Y and other similar models. ATTENTION. When working with a power supply on the STR-S6707 chip, be sure to discharge the 220x400v storage capacity.

Fault: when the network is turned on, the standby indicator starts blinking frequently. Faulty capacity C826 220.0x35v in the Q805 KTD2092 circuit.

Fault: low brightness. When adding brightness accelerating with TDKS, personnel stops working: a narrow band. The 9v stabilizer turned out to be faulty: power supply to 1 leg of the personnel microcircuit.

Fault: TV may or may not turn on. But if it turned on, when the TV was switched to standby mode, the standby indicator went out, and the voltage at the outputs of the secondary rectifiers increased by 2-2.5 times. A similar malfunction must be sought in the stabilization device. In this case, the R814 resistor (12k) in the IC801 optocoupler LED circuit turned out to be faulty.

GoldStar 9322B (chassis PC-05X2) when turned on, it fills with milk, the brightness and contrast adjustments do not affect, I hung the 8th leg of the TDA3562A video processor (analogous to KR1024XA4) through 1 MΩ to +, the image began to look slightly. Replacing the chip did nothing. I rang the transistors on the kinescope board - everything is ok! I decided to replace the Q907 2SA1015 transistor, the tester calls normally. After the replacement, the TV worked.

LG CF-20F39. Fault: no image. There is a vertical line on the screen. The capacitor in the line coil circuit is faulty (it seems C412) with a nominal value of 0.36 uFx400 V - open. On the appearance you will never think.

LG CF21D30 chassis MC-64B after replacing TDKS, burned-out R424 10kom, pierced by D401. Fault: The TV starts and after a few seconds goes into standby mode. Each subsequent activation from the remote control reduces the operating time. As a result, it turned out to be a broken transistor Q302, which sends an ABNORMAL pulse to the 20th leg of the processor.

LG-CF21F60K, processor TDA 9381 PS / No. 2 / 3 / 0533 Fault: white oblique stripes on a dark screen, light snow appears when the antenna is turned off. According to the hostess, the image disappeared when the video camera was connected to the low-frequency input N.Ch. Connecting 42 pins of the processor (input of external video) through a resistance of 1 K to the ground - restored the work of TV on V.Ch. and according to N.Ch.

GoldStar CF-14A80Y, CF-20A80Y, CF-21A80Y MC-41A chassis. CPU IC01 GS8334-09A (GS8334-09C) Fault: There is no sound in TV mode, there is in AV mode. During tuning to channels, it does not stop (it skips stations). Leaked Q06 2SC3198.

GOLDSTAR CF20E20B Fault: No picture or sound. Upon inspection, I found that there was no power to the TA8690 video processor. The reason - the stabilizer IC402 (KIA7809) failed. After replacing the chip, the TV started working.

GOLDSTAR CF20A80 Fault: turns on on any random program, when you press the program switch button, a menu pops up, etc. Replace memory 24CO2.

LG CT-15Q91KE Fault: no raster. According to the client: Clicked and went out. There is sound, it is adjustable. Channels are switched. When an accelerating voltage was added, a gray raster with OX lines appeared. There is no video signal and no OSD. When switching channels - a slight attenuation of the raster. The OX lines are stationary - they do not respond to the presence or absence of a signal at the antenna input. Assembled on IC TDA9381PS/N2/3I0792. All supply voltages are normal. FB, SSC, etc. in. impulses are normal. The strapping has been checked from and to, including on the kinescope board. The signal from the RGB outputs to the cathodes comes normally. At the RGB outputs of the IC (pin 51, 52, 53) absolute zero. At pin 50 of the IC (BLKIN - black current input) + 7v. I did not find the circuit, the normal voltage is unknown. I tried grounding. Result: An image appeared, but with OX lines. On red - flags, but the brightness is normal. The voltage on the cathodes is the same - about 150V. I alternately short the RGB outputs to ground. After closing R, an image without red color appears. By selecting the resistance of the resistor between the output IK (IC TDA6107Q) and the ground, the image appeared without OX lines. Denomination - 10 room. The image is bright, except for the flags on red. Conclusion: Loss of emission of the red cathode of the kinescope due to a high-voltage discharge inside the tube. As a result, the cathodes of the microtext processor IC are blocked. So don't forget to check the cathode emission currents.

LG CF-21F30 Fault: no start. The power supply is assembled on the STRS5707. Dry S824 4.7x50v

LG-21D33 (MC-84A chassis) Fault: after 1-1.5 hours of operation, the TV periodically switches off to standby mode for several minutes. Then it goes into standby mode and does not react to anything. To turn it on again, you need to disconnect from the network for ~ 0.5h. The reset circuit IC03 KA7542 turned out to be faulty.

GOLDSTAR CK21A90 Fault: does not turn on (shortly before the breakdown, it turned on once). The power supply is broken (1.5 mΩ is called) R802 680 com.

LG CT-25Q20RQ Fault: does not turn on, the standby indicator does not light. In the R830 break (such as a resistor-fuse, a 0.47 ohm resistor is installed instead), it is in the secondary, +12 volts is supplied through it.

Gold Star CF-29C44 chassis MS-51A. Fault: When turned on, after 2 seconds it returns to standby mode, high appears. The device came after an unsuccessful repair. They changed the processor, memory in it, they plowed everything. And all because they did not read<Секреты ремонта>. Repair took 15 minutes. Of these, for 10 minutes I was looking for the position number IC7P (very inconspicuous) on the PIP board - Krenka 78L08. When measured at the moment of switching on, 4v appeared at its output instead of 8v. After replacing it, everything worked.

LG CF-21J50K, CT-21Q41KE chassis MC 019A Fault: the power supply does not start (clicks). Replacing the line transistor TT2140 with 2SD2499 and TDKS 6174Z-6040C analogue of HR8656 (if there is a short circuit on all pins of the line transistor, you will probably have to change TDKS, there are marriages of TDKS-s manufactured on 09-11.2003) in my practice there are three Russian-assembled LG TVs different brands, but with the same chassis and all the multipliers "died", and the windings are intact. TVs are still under warranty.

LG CT-29K30VE chassis MC 022A Fault: no image and raster (screen is black), there is sound, when the accelerating voltage increases, the screen is greenish with reverse lines, when switching channels, the image appears for a second, but without a blue tint and disappears again. Replacing the TDA6107JF video amplifier did not change anything, only after detailed check The strapping turned out to be leaking diode D903 on the kinescope board in blue, after replacing it with ours from MTs-2 (there was no native), the image appeared.

LG RT-21FA32X Fault: TV does not turn on from standby mode. It turned out to be faulty C820 200.0x160.

GoldStar CF-20E20 (power supply assembled on STR-S5707). Fault: to turn on the TV from a cold start, it was necessary to press the network button 10-15 times. To eliminate the malfunction, it is necessary to replace two containers: C820 and C825, both 220.0x35v.

Goldstar CKT-9902. Fault: When turned on, a black arrow 5-10 cm wide is visible on top of the screen, the direction of the arrow is from left to right. Beautiful clearly traced arrow with a head at the end in the form of a crescent. The arrow disappears 5 minutes after switching on. The reason is the voltage boost capacitor in the frame scan of 100 microfarads, installed near the frame chip.

LG CF-21D30 Fault: at different intervals it goes into standby mode. Replace C408 and preferably change C311 and C824.

GoldStar CF20A80Y Fault: I press the program switch button on the front panel, anything is displayed, only the channels do not switch. It is necessary to reflash the 24C02 memory chip on the programmer.

LG CF-21D31KE. Chassis MC-019. The sound is accompanied by unpleasant overtones, it seems that either the loudspeakers or the ULF are defective. But the test showed that they are normal. The cause of the malfunction was the TDA9859 audio processor chip.

LG RT-21FB30M. Fault: no image, black screen, OSD present. The IF signal does not pass, there is no video signal at pin 40 of IC01 (CVBSINT) - transistor Q551 (2SA1980) is broken

Goldstar CF-21A80Y. Fault: APCG does not work, there is no signal identification. Defective GS8334-09C processor. Replaced by GS8434-03B. For compatibility with the native remote control, replace the 4.0 MHz quartz with 3.6 MHz.

Gold Star (chassis MC64A) Fault: after switching +V jumps to 160V and the internal protection in STR-S5707 is triggered. The reason is C824.

GoldStar CF21A80Y Fault: blurry image (no focus). I checked the voltage with the TDKS-norm, I thought the tube was faulty, just in case I dismantled the kinescope block, the focusing arrester was oxidized (all blue-green), the copper remained, I cleaned the oxide with a brush, the TV got an excellent picture.

LG CF-20J50K (Chassis MC-019B) - Malfunction: the image is shifted to the right by 10cm, there is color and synchronization. Breakage of C505 (222J) of the filter of the 2nd circuit of the APCIF.

LG CF21F60K chassis 019A Fault: dark screen, with the addition of an accelerating weak picture with a reverse beam, there is sound, there is graphics. Faulty R456 open circuit ABL, after replacing the TV is working.

LG CF21F60K chassis 019A TDA9381PS\N2\3 changes to TDA9361PS\N2\4I0793 (from LG CT-21Q42KEX).

LG RT-29FA55RB MC049A Fault: the TV does not exit the standby mode protection is triggered, you need to replace the TDA6109J. I tried to replace it with TDA6108J: the TV turned on but after 15 minutes it goes into standby mode, it is necessary to replace it with TDA6109J.

GOLD STAR CF-29C36X. Chassis MC-51B. Fault: the TV does not turn on from standby mode, when turned on, the DR indication LED lights up green, after a second it turns red and so on. If you remove Q803 (C3228) the TV turns on, the horizontal line starts up, but the screen is dark. Faulty IC351 TDA8350Q. After replacement, there is a "wrinkle" in the vertical image due to an increase in the resistance of the breaking resistor FR359 (10 Ohm - 0.5 W) for +45 V supply. Replaced, as well as FR351 (2.2 Ohm) for +20 V supply.

LG CF-21D30 chassis MC-64B. (The power supply is assembled on STR-S5707) Fault: when turned on, the red LED on the front panel starts blinking constantly at a frequency of about 2 Hz, relay clicks are heard in time with the blinking. The TV does not respond to either the remote control or the control buttons on the front panel. Left it on like this. After about 10 minutes, a wisp of smoke appeared. The problem found itself. A small capacitor C813 470pFx1000 V smoked in the secondary circuit of the power supply (it shunts the rectifier diode + V). After replacing it with a capacitor close in parameters, the operation of the device was restored.

LG-CF20F39 (chassis-MC994A) Fault: no power supply start, line transistor 2SD2449 broken. In the harness I noticed "familiar" capacitors from WOOYANG. One of them is 0.334x400 in a cliff. Although TVs have a vertical thread with such a malfunction, the transistor does not knock out, so I also replaced the capacitor with 1600 volts (it is also from WOO YANG).

GOLDSTAR CF-20D70B Fault: no color in the SECAM system. As a result of the search, a faulty Q512 2SC3198Y was found. I jacked up the voltage at the 13th output of the processor to 2 volts.

Goldstar CKT-9742. Processor SAA1293-02. Fault: all signs of an MDA2062 memory failure, (incorrect operation of the buttons on the front panel, etc.). Entrance to the service with the RS-4 remote control, selection of optional bytes with the SERV button, changes are saved automatically. I set the option bytes in the same way as SAA1293-03 (as in 4USCT).

GoldStar CKT9745 (PC-91A) Fault: does not turn on, relay clicks. Faulty R805 -820k in PSU.

GOLDSTAR chassis MS-41A. The LG8634-02A microprocessor will be replaced by the GS8334-03B. The only difference is in the RGB piping for sending signals to the video processor.

GoldStar chassis MC-51A. Fault: a second after switching on, it turns off in STBY. The famous roll 1C7P (7808) has nothing to do with it, just like the PIP board itself. After several unsuccessful hours to revive the TV, IC806 (KIA7809) was found next to the PSU, which gave out 4 volts at the output. After replacing it with KREN8A, everything worked.

Goldstar CKT-4822. Fault: no image. Is there sound. The screen glows only if you add an accelerating one. Everything seems to come to the TDA3561A video processor (it was changed before me, but the result was not achieved). The problem was in his diet. The device showed the required 12V on the first hoof. It is necessary to replace the electrolytic capacitor 330.0x25V, which stands in front of the KRENka 12V after the diode (power comes from a horizontal trance). It should be noted that after the above replacement, the TV worked, but badly. I had to replace a few more electrolytes to power different cascades.

LG CF 20S10E. Fault: TV does not turn on. Composition: ICO LG 20S10E IC 501, TDA 8842 S1. The problem is in the resistor assembly AR02 4.7k 9n in the open: 0 ohm. Replacing the AR02 4.7k assembly restored the TV's work. Also 1204 1184. To the above, we can add: the failure of the TV to turn on in the operating mode occurs when AR02 fails and when AR01 fails. But if AR01 fails, the memory is always intact! And when AR02 exits, a memory failure is possible, even a horizontal scanning transistor failure.

GoldStar CF-20D60B, Fault: the mains fuse is on, the STRS6707 in the power supply is out of order. Be sure to check and, if necessary, replace C825, C826. Otherwise, the STRS6707 may fail again.

LG-21Q42KEX Chassis MC-019. Fault: no horizontal and frame synchronization, there is sound. Replaced processor TDA9361PS/N2/4I0793 (OICTMH006C).

GOLD STAR CF-14A80B chassis MC-41B. Fault: a decrease in the number of channels received by the TV. The VH range (+12V) on the tuner is constantly on due to leakage of the Zener diode Z003 (7V5) in the control circuit of the Q11 DTA114 key.

LG CF20E20 Fault: Unpredictably turns off to standby mode (after ~ 3 ... 30 min.). Cause: Loss of capacitance C408 1.0mkF 160V in the line scan pre-output filter. On a faulty conder, the cartoon showed 42V, after replacing it 33V. Oddly enough, the temperature of the output transistor was normal.

LG CF-21D30. Malfunction: the TV does not respond to the channel switching buttons, confuses commands with the remote control, periodically goes into standby mode. Faulty m / s PROM 24S04. Replace with a new one, you can not stitched.

LG PT-53A82T Fault: convergence "ran up", specifically - the red beam on the cross in the menu option does not converge. Faulty STK392-120 datasheet, there are two of them - on the blue and red projector. After replacement everything is fine. Attention - a real STK costs about $35.

GOLDSTAR CKT-2190, SHIVAKI STV-206M4 assembled on PC-04A chassis automatic tuning skips programs, with warming up, the defect may disappear. After the diagnosis, it turned out: the electrolyte C409 0.22mk dried up on the 5th leg of the TDA1940 according to the scheme.

Goldstar SKT-2190. Fault: increased brightness, dimming on the left side of the screen with a change in brightness. Replace C431 2.2x250v (power supply for video amplifiers).

LG CF-20F39 Chassis MC994A. Fault: entered for repair with an old TDKS, the resistor in the ABL circuit also burned out. TDKS has already been changed by someone. After replacing the TDKS and R 33k, the TV started up. When measuring the supply voltage lines found its smooth increase to 150-160V protection did not work. Troubleshooting the stabilization circuit in the PSU revealed a dead IC801 optocoupler. Replaced with PC120, everything went as it should. Linear tr-p in this chassis without a heatsink, I think this is LG's flaw - fix it! I will not repeat about WOOYANG capacitors.

Goldstar CFZ-9822. Fault: TDKS 154-177E failed. This TDKS has a Booster output. Such a TDKS is a deficit. It is possible to change it to the common 154-177J. Minimum alterations: Wind 5 turns of insulated mounting wire onto the TDKS core, solder one end to the 3rd TDKS output (92 V from the PSU), the other end to + C705 100 x 63 V (booster). Determine the winding direction experimentally, if you mix it up, nothing catastrophic will happen, just all the secondary voltages of the TDKS will be underestimated. Cut off the tracks from pins 5 and 6 of the TDKS and swap them (these are voltages of 12 and 24 V.) You can not cut the tracks, but raise the resistors connected to them and solder them crosswise. Cut off the track from the 4th output of the TDKS and connect it to ground. Cut off the track from pin 7 of the TDKS (do not connect it anywhere, since this pin is 40 volts at 154-177J) All other pins are the same. The number of turns of the wound additional winding changes all the secondary voltages of the TDKS in direct proportion. (more turns - more voltage.) If in your case the voltages are too high (or too low), adjust the number of turns to suit your option. I selected the number of turns and controlled the output voltages of the video amplifiers (180 V), and only then checked the rest.

LG CF-20D70 Chassis MC-64A Fault: no line scan start. D408 1N4148 turned out to be faulty, although it does not show a leak when checking, even with a digital device.

GoldStar SF-21E20B. Fault: after 30 - 40 minutes after switching on, it goes into standby mode, which is accompanied by the blinking of the LED on the front panel. The subsequent inclusion in the operating mode was possible only after "cooling down", and for a period of no more than 30 - 40 minutes. The reason is poor soldering of the leads. pulse transformer power supply. After soldering all the leads, the normal operation of the TV was restored. The defect was discovered only after a thorough inspection. printed circuit board through a magnifying glass.

Goldstar CF-20D70B. Chassis MC-41B. Fault: after several minutes of operation, a group of embossed lines appeared in the upper part of the raster, and when working from the video input, such a defect was not observed. The reason turned out to be in the IC201 (LA7222) switch chip - it "squandered" the video signal.

Goldstar CKT-9902. Chassis PC-04A. Fault: when switching from standby to operating mode, the indicator LED goes out, but the device does not turn on. The reason turned out to be an open diode D401. It is in the power circuit of the horizontal scanning pre-output stage. Replaced with diode D226D.

GoldStar CF-21A80Y, aka CF-20E20B chassis MC-41A. Processor GC8334-09B memory 24C02. Fault: when turned on with the network button, it spontaneously switched to operating mode on 89 or 91 channels. The buttons on the front of the TV turned on everything except what they were supposed to display. After replacing it with a clean memory and tuning to channels, everything was restored.

LG Chassis MC-64A. Fault: after turning on, after a while, a popping sound appears and, in time with this sound, a raster begins to appear, which gradually expands horizontally to full size. Diode D408 (1N4148) is leaking. It stands next to the famous capacitor C408 along the ABNORMAL circuit.

GOLDSTAR-CF20A80 (chassis MC-41). Fault: quiet sound with distortion. Applied audio conversion from multi-standard to IF=6 MHz. The 6.0 MHz SFE filter to the 49th leg of the TA8690AN has failed.

LG CF-20F30 Fault: does not start. We turn off the line scan, connect the control light. The power supply unit started up; the control lamp lit up; all voltages appeared. However, it was not possible to identify a malfunction in the scan. I had to go back to the power supply. It turned out that the capacitance of C824 4.7x50V was lost up to 2.8 microfarads

LG Model CF-20F80 Chassis MS-84A Fault: received for repair with a fault no picture sound is normal, although the service information is displayed normally. At high magnification on the SCREEN line, a very faint inverted image appeared on the screen along with retrace lines. The cause of this malfunction was the Zener diode ZD741 8.2V on the ABL line. After replacing it, the picture appeared, the TV worked fine.

LG RT-21FA72X Chassis MC-019. Apparatus after a thunderstorm. Fault: when turned on, an image appears for a second and immediately turns off to standby mode. The processor TDA9381PS/N2/4/0703 (OICTMPH006B) is to blame. Successfully replaced by TDA9381PS/N2/4I0793 (OICTMPH006C).

LG CF-20K50E chassis MC-019. Fault: does not turn on from standby mode. On the 4th leg of IC803 (STRF6654) 13 volts instead of 18.9 volts. Faulty C801 (100.0x35V).

Goldstar CF-21E60X chassis MC-64A. Fault: turns off in standby mode at different intervals. Reason: breakdown of D401 (1N4148) and leakage of transistor Q302 (2SC3198). After the replacement, the TV stopped turning off.

LG RT-21FB30M Chassis MS-019A. Fault: TV after a thunderstorm. When turned on, a raster appears, but there is no image and sound. The menu turns on, all control buttons work. The setting turns on, but finds nothing. The IC01 TDA9381PS/N2/3I0792 (OICTMPH010A) processor was to blame. After replacing everything worked.

Goldstar CF-21C22X chassis MS-46A. The TV does not turn on. When you try to turn it on, the indicator goes out, but there is no voltage at the output of the power supply. A broken transistor Q812 (KTC1026) was found in the power supply. There are no changes after replacement. Next, transistor Q2 (KRC102M) was found in a leak (replaced by DTC114ES) and IC807 (KIA7812P) in a break. After that, the TV began to turn on, but when it was turned off, the raster and sound disappeared, and the sweeps continued to work. Found transistor Q105 (KRC102M) in the leak (replaced by DTC114ES). The device worked fine.

GoldStar CF-20A80Y chassis MC-41A Fault: during a cold start, the TV turns on poorly (from the 10th time), the hum of the pulse transformer is heard, as well as an unpleasant hum in the dynamics, the output voltages are underestimated. There were dried capacitors in the power supply C815, C820 10.0x100V, C826 220.0x35V

Goldstar CF-20A80Y chassis MS-41A Fault: when the TV was turned off from the socket or the power button, the settings were reset to the factory settings (brightness, contrast, turning the TV on and off) IC02 24c02P turned out to be faulty

LG RE-29FA33X Fault: the image periodically disappears and after 5 seconds. goes on the defensive. Established the disappearance of personnel. The reason is the cold soldering of the legs of the TDKS - all except those mounted on rivets. The legs of the TDKS are covered with a plastic frame for a monoplate.

LG CF-20E20 Fault: the TV does not turn on, the LED does not light up. Discovered, K.Z. powerful transistor in STR S 5707, 120 ohm leakage in 4N35GV optocoupler between 4 and 5 legs. C820 220uF 35v and C825 220uF to 35v have changed their capacitances. I replaced everything, the TV does not turn on, the LED does not light up. I measured C - with a C824 meter 4.7 microfarads at 50v - the norm, but ESR is more than 30 ohms, I replaced C824 and the TV began to work.

LG CF-21J50K chassis MS-019A Fault: the TV is on, no reception on any channel, no sound. The TV works on a low frequency. In the service mode of the TV, as for the selector and IF, it corresponds to the tabular data. I checked the data bus and the clock bus with an oscilloscope, rectangular pulses filled with higher frequency are available. The channel selector voltage matches. I disconnected the IF - selector, applied the IF from another TV, the image appeared. With the help of Laspi-TT-03, it is impossible to check the inverter, the signal level is low. I replaced the selector and the TV began to work.

LG CF20E20 Fault: the TV works, but on different bands with different time intervals, it goes into standby mode. By pressing the program switch button on the remote control, the TV works again for 20 sometimes 30 minutes. On the IC01 processor on the 20th leg of AVNORMAL, the voltage changed and put the power supply into standby mode. C408 1.0x160 volts, in my case: the s-meter showed normal capacitance, and the ESR meter was more than 30 ohms.

LG 20E20 Chassis MC-64A. Fault: the power supply on the STR-S5707 does not turn on. The reason is the loss of capacitance of the capacitor C824, which is on the 7th leg of the microcircuit. Apparently this defect is due to a not entirely successful place for its installation - between the radiator fins.

Regardless of the TV model (whether LCD, plasma, projection or regular CRT), it is necessary that it meets your personal requirements for TV performance. The most relevant and sought-after features that are crucial when buying a TV are listed on the pages of our illustrated catalog. The size of the TV screen, or rather its diagonal, can be indicated in two sizes - centimeters or inches (in most cases it is indicated in the title specific model). This parameter is responsible for the most optimal distance from which it is recommended to watch TV. As for liquid crystal (LCD) and plasma TVs (plasmas), the diagonal, or rather its size, is also very important. The thing is that when watching TV at close range, the image can seem very grainy. It is also worth paying attention to the screen format and the function of changing the screen format. To watch TV programs, it is best to use TVs with a 4:3 aspect ratio. To view DVD discs It is better to use TVs with a 16:9 aspect ratio. But most models modern TVs support both of these formats, but it is better to clarify this point when buying.

High-quality sound is far from the last place when choosing a TV. From small TVs to demand good quality can't because of short distance between speakers. Therefore, on TVs with a diagonal of up to 54 cm, mono sound can also be acceptable. But if we are talking about quality television, watching DVDs, satellite television, about modern digital cable television- you can't do without stereo sound.

TV control - very important point. A good, well-thought-out menu and remote control will help you to use all the necessary functions of the TV without any problems, besides, you will get used to the well-thought-out menu very quickly. Remote TV controls should not be too bulky and well balanced in the hand. It is very convenient if the buttons are pressed hard, but clearly. And it is desirable that they have ledges so that you can find the desired button in the dark by touch. Also, it is desirable that on the TV itself there is a dubbing of all remote control controls.

Well, the last thing you definitely need to pay attention to is the TV connectors. In addition to the antenna input, it is desirable that the TV contains connectors such as "bells", SACRT, S-video and others. This will allow you to connect different equipment to the TV. Also, for high-definition TVs, the presence of HDMI is important.

Hi all!

This article will focus on the simplest, but at the same time the most common, malfunctions of LG CRT TVs with a diagonal of 29 inches (72 cm).

Such malfunctions can be dealt with with the skills of working with a soldering iron, as well as having normal vision. No more skills, except for holding a screwdriver in your hands, in this case, are required.

We will develop this topic on specific example, i.e. we will produce TV repair LG do it yourself .

So, I entered tv repair LG, model 29FS4RN, chassis MC-05HA.

According to the client, the TV periodically switched to standby mode during viewing (it turned off, but the indicator on the front panel glowed red). Then, one fine evening, the TV was turned off by the remote control, and the next day it did not turn on. Only after that the client realized that something was wrong with the device, and thus this television receiver ended up with me.

I must say right away that the malfunctions that will be discussed below are very typical for CRT TVs with a large screen diagonal, so tips for fixing them will be relevant for any brand of TV.

I made a trial inclusion of this unit and, indeed, the standby mode indicator glowed red, but the TV did not turn on in the operating mode.

Next, I proceeded to disassemble the faulty device, namely, I unscrewed the back cover.

Then I removed the chassis (board) from the case.

Attention! When disconnecting the chassis from the kinescope, be careful! In any kinescope, there is always a large current charge. Therefore, by disconnecting the high-voltage wire coming fromTDKSto the anode terminal of the kinescope (suction cup), use a well-insulated screwdriver (or something like that, non-conductive electricity). Slide the screwdriver under the suction cup, press the contacts under it and gently, without touching the metal part of the screwdriver and contacts with your hands, pull the rubber part of the suction cup to disconnect it from the kinescope. Remember, the current going to the kinescope anode has a voltage of 25 kV (25,000 volts).

Also, do not touch the contacts of the power capacitor with your hands (it is in the primary power circuit, it is also called the “jar” because it is the largest) while the charge is stored in it. In no case do not discharge it in the board itself by closing the contacts - this can lead to failure of the power microcircuit. It must be carefully removed from the board, and then, at arm's length, bridge the contacts with an insulated screwdriver, thereby discharging it. And then solder in place, observing the polarity.

In order not to forget the location of various cables and wires that are disconnected from the board when the chassis is removed from the case, you can take a few photos so that you don’t get confused when connecting.

I will announce the composition of the LG TV on the MC-05HA chassis:

UOC - VCT6743G B3 080 (processor)

EEPROM - AT24C16A (memory)

SMPS-STR-F6458

TR Chopper - 6170VMCB16P

STBY-STR-A6151

Multistandard TV Digital - STV2310SD

Vertical - LA4876N (personnel)

Sound - TDA7297 (sound)

Tuner - TAUD-S210D / 6700SP0001A

TV/AV - LA7222

FBT - 6174917003A BSC30-N2570 (TDKS)

HOT - 2SC5858 (linear transistor)

RGB Amp. — LM2423TE

Remote control: - 6710V00145J, 6710V00112V

Entrance to service mode: Turn the TV on and press MENU on the TV and MENU on the remote at the same time.

Exit is OK.

Download TV diagram LG, chassis MC-05HA, as well as TV firmware , you can from "» of this website.

After removing the chassis, I started visual inspection of the board.

First of all, I looked for swollen capacitors. If suddenly you find capacitors on the board that have even the smallest swelling, feel free to change them to known good ones, or better to new ones.

When replacing capacitors, keep in mind that they are polarized, i.e. have “+” and “minus” outputs, and are installed on the board accordingly.

So, faulty capacitors at visual inspection was not found.

Then I turned the chassis upside down, took a magnifying glass and, with an “armed” eye, began to examine the board for microcracks and non-solders.

During such an inspection, I found several cracks in the area where the TDKS contacts were attached (diode-cascade line transformer), as well as delamination of some reinforced contacts in the same area.

A reinforced contact is a contact that is attached to the board not only with solder, but also with a metal washer.

After that, I soldered the cracks in the board with wires. During this procedure, I found another crack in the primary power circuit, which I also soldered with wires.

I also soldered all the reinforced contacts that are on this chassis. I soldered everything, because there were cases when such a contact peeled off the board and it was very difficult to notice it.

After carrying out all the activities outlined above, it was necessary to install the chassis back into the body, which I did.

Well, it's time for the first post-repair switching on the device. What I did, see the photo below:

As you can see, the TV is working.

That's all. Everything about everything took me about 40 minutes of time.

Agree that there is nothing particularly difficult in this repair.

If, having examined your TV in this way, you did not find anything of the kind, and if at the same time you do not have certain knowledge of repairing radio equipment, then it is better to contact a professional so as not to aggravate the problem with your actions.

Choosing a CRT TV

A cathode ray kinescope (also called a cathode ray tube, CRT) is a technology that has come down to us from the last century. Serial production of the first televisions that worked on this principle began back in 1939. Nevertheless, such a venerable age of this technology is rather its advantage than a disadvantage, because CRT TVs are still used today, which means that they fully satisfy the needs of those who like to spend their free time at blue screens. So in this case, the condescending phrase " last century” does not mean “junk” at all, but time-tested traditions.

In our time, the most widely used, the most "advanced" consumers already have an idea about the principles of operation of these devices. But some potential buyers are unaware of what is inside the case of a CRT TV.

The device and principle of operation of a kinescope TV

As mentioned above, the main element of an old-style TV is a cathode ray kinescope (in the English version of Cathode Ray Tube, CRT). In this device, the process of forming a television "picture", which is then displayed on the screen, takes place.

In the figure, the numbers indicate:

1 - electron guns (three for color TVs, one for black and white);
2 - electron beams;
3 - focusing coils;
4 - deflecting coils;
5 - anode output;
6 - shadow "mask", filtering out the red, green and blue parts of the "picture";
7 - a layer of phosphorus-containing phosphor covering the inner surface of the screen, with areas of red, green and blue glow;
8 is an enlarged view of the phosphor coating on the inside of the screen.

In fact, cathode-ray tube is a glass flask, inside which a vacuum is created. Under the influence of electricity, electron guns (1) begin to emit rays (2) that pass through the kinescope tube. These beams, which are directed electron flows, are captured by a system of focusing and deflecting coils (3, 4). Electromagnetic coils redirect the beams to the anode terminal (5), which supplies electrons to the filter mask (6), which separates the total stream into color components. In the oldest models of black and white TVs, the color filter, of course, was absent.

The process of appearance of the image on the screen can be described as follows. After the formation and filtering of the light fluxes, the rays fall on the inner surface of the television screen (7), which is invisible to the audience. The phosphor coating consists of red, green and blue particles that glow when exposed to a beam of the corresponding color. The surface covered with a phosphor is not fully illuminated, only individual particles of the substance are illuminated - thus, the rays sent by the anode output form a rapidly moving light spot on the screen. This spot moves across the screen line by line, from left to right and from top to bottom, but the movement is very fast, imperceptible to human eyes, so the viewer sees a complete image. Accordingly, the higher the screen refresh rate (the period of “running” of the light spot from the first to the last point), the better the image is obtained.

The kinescope tube is located perpendicular to the screen surface, which means that it takes up a lot of space under the TV case. That is why the case of such a device has such impressive dimensions and it is impossible to make it super-thin, like modern plasma or LCD TVs, for purely technological reasons. It is not surprising that kinescope devices have received a tender nickname among the people - "boxes"!

The main technical characteristics of kinescope TVs

Now that we have a general idea of ​​​​the operation of the kinescope, we can begin to choose a TV. In principle, the main parameters to be guided by when choosing are quite obvious. However, inexperienced buyers may not pay attention to enough technical details that spoil all the pleasure of watching your favorite series or an important sports match.

1. Screen size and shape

When purchasing a “window” into the vast world of television, it is important not to miscalculate with the size, otherwise you will not be able to see much. Obviously, TVs with the largest screen sizes differ large dimensions, so the owners of small living rooms will have to moderate their appetites. In CRT TVs, as the screen size increases, not only the height and width increase, but also the depth of the case, which means that relying on a large screen, the unlucky buyer may face a big problem: the new thing will take up too much free space in the room.

The smallest CRT TVs have a diagonal of 10 inches - viewing programs on them cannot be called comfortable. The optimal minimum is 14-15 inches; TVs with such parameters are produced by almost all well-known companies. Screens with a diagonal of 20 to 25 inches are even more popular. TVs with such dimensions fit perfectly into the average apartment and, as a rule, have full set most requested features. The largest are 29-inch CRT TVs, but models with a 34-inch screen can also be found on sale. These are real giants, they are suitable only for very large rooms and are usually installed on special cabinets supplied as a set or by order.

When choosing a TV, it is important to remember such a parameter as the most comfortable viewing distance.

Based on this table, it is easy to determine the approximate location of furniture in the living room seating area, namely, the distance at which the TV stand and sofa or chairs should be spaced apart. When purchasing a CRT TV, it is necessary to plan in advance the place of its installation. If it will stand in a furniture niche, then a prerequisite is the presence of a gap between the walls of the niche and the body of the device, while air access to the device must not be blocked. ventilation holes. Otherwise, the TV will overheat and fail.

The screen size is also important. With a classic width-to-height ratio of 4:3, it's best to watch regular TV shows. Wide screens with a 16:9 aspect ratio are ideal for watching movies, so if the TV will be paired with a DVD player most of the time, widescreen is preferable. There are several other less popular formats that allow you to get an image with minimal distortion. Modern TV models have an automatic format adjustment function.

Screen ratio

The sharpness of the image depends on the geometry of the screen. A convex kinescope distorts the “picture” quite strongly. To get the most realistic images, it is better to purchase a TV with a flat or super flat screen.

2. Sweep frequency is one of the indicators of image quality. In accordance with the principle of operation of the kinescope described above, the image on the screen appears due to the glow of phosphor particles. It is the sweep frequency that determines the speed at which the light spot moves across the screen. In older TVs, this figure was 50 Hz, so it seemed to the viewer that the “picture” was flickering. When watching TV for a long time, the unstable image caused severe eye fatigue. Modern kinescopes provide a refresh rate of 100-120 Hz - this indicator is considered optimal for large-screen TVs, where image instability is especially noticeable.

It should be noted that at a screen refresh rate of 100 Hz, the effect of a loop from objects moving quickly in the frame is sometimes observed. To stabilize the "picture" manufacturers use special technologies. When purchasing a large-sized TV, you should pay attention to image stabilization technology: for Digital Plus, for Digital Scan Natural Motion, for Super Digital, for Digital Mastering or Intelligent Mastering, depending on the model.

3. Speakers

Television programs are not only a visual range, so powerful and high-quality sound is one of the main technical characteristics. Smaller TVs are often equipped with single speakers, while larger models only have stereo speakers. Regardless of the number of speakers, they are always located on the front surface of the case, usually below or on the sides of the screen.

Standard speaker layout below the screen (left) and on the sides of the screen (right)

Expensive modern CRT televisions often have built-in subwoofers that transmit low-frequency sound, and surround sound systems made using Dolby Pro Logic or Dolby Digital technology.

4. Connectors for connecting external devices

As you know, a TV cannot work on its own; to receive a signal, it needs external antenna or digital cable. Perhaps, among modern TVs it is impossible to find a single model that would be equipped only with an antenna connector. For full use, you also need, at a minimum, audio and video outputs, to which you connect a VCR and DVD player.

Minimum set of connectors: TV antenna jack and RCA connectors for audio and video signals

In addition, the set of connectors will not be superfluous analog VGA port and universal SCART port - you can connect multimedia equipment, satellite or digital receiver to it.

5. TV control method

Remote controller remote control has long been an invariable attribute of the TV. This simple and easy-to-use device allows you to change channels, adjust the volume level and perform many other tasks without getting up from the couch. Nevertheless, on the front panel of the TV, as a rule, you can find the main control buttons that duplicate the corresponding keys on the remote control, usually these are the power button, volume controls and channel navigation buttons.

Control buttons located on the TV case

When choosing a TV, you should not buy such a model, on the body of which the entire set of control panel buttons would be duplicated - such a device would be too bulky. Only the main keys are enough, which can be used if the batteries are dead in the remote control.

Advantages and disadvantages of CRT TVs

Since with the main technical specifications We have already figured out CRT TVs, we still need to consider the strengths and weak sides these devices.

Advantages:

• low price;
• a wide variety of models;
• good image quality;
• realistic color reproduction;
• long service life (about 15 years).

Flaws:

• large dimensions and weight;
• negative impact on vision during prolonged viewing.

Do-it-yourself TV repair is a responsible business, since today a large number of different models (LCD, LSD, kinescope) are on the market, each of which has its own technological features. Therefore, the approach to each type of TV is individual; in some cases, special skills will be required (knowledge of electronics, experience with a soldering station).

Before proceeding with the repair of television equipment, it is necessary to find out the cause of the problem.

The most common problems:

1. TV screen does not turn on- this can happen with the old kinescope screen and with the most modern television panel. Basically, this symptom is characteristic of a blown fuse. When repairing, you should take into account the fact that for each model you need to select the appropriate fuse. And also experts recommend paying attention to the diode bridge, power supply, wire, perhaps the cause of the malfunction lies in these elements. Read also.

1. Dim, barely noticeable picture- such a breakdown happens with LCD / LCD monitors. Most probable cause malfunctions: failed diodes, device backlight.
2. There is no sound, the screen "wheezes"- most likely, the sound amplifier or microcircuit has failed. Read also,.
3. Monitor lights up, no picture– perhaps the cause of the problem is in the video processor or in the receiving unit.

You should be aware that if a darkening of the board or a break in the elements is detected during a visual inspection of the television equipment, then it is not recommended to immediately start replacing parts. Since such factors indicate a short circuit that could occur in another department of the TV. Therefore, if you do not eliminate the cause of the short circuit, but simply change the failed elements, then the situation will repeat.

What tools will be needed

The following tools and techniques may be required to repair television equipment:

• Screwdriver Set;
• hex keys (in rare cases);
• pliers;
• soldering station (for repairing modern monitors);
• screen layout (can be downloaded from the Internet);
• multimeter;
• oscilloscope.

Features of repairing LCD TVs

Many problems with LCD screens can be completely dealt with on your own. But you should be aware that these screens require more careful handling than, for example, CRT TVs.

First of all, the user needs to study the instructions for his model, and only after that proceed with the repair of the LCD or LED screen. You should know that LCD TVs are backlit with fluorescent bulbs, and LEDs are used on LEDs.

It is possible that the TV does not function due to a lack of power, to check this, you need to follow these steps:

1. Open the back cover of the LCD TV with tools.
2. Disconnect the wires that are connected to the device matrix.
3. Connect a working light bulb to the contacts.
4. Some panels have more than one light source, in which case they must also be tested. You can do this as follows: pull out the TV matrix and connect it to the network, it will immediately become clear which lamp is out of order.

After a faulty lamp is found, it must be replaced. This procedure must be carried out with the utmost care. In most cases, the lamp can even be removed without removing the matrix - you need to move the protection elements and remove the burnt part using a soldering station. Then a new lamp is installed in the same way. An important rule is that the new lamp must be completely identical to the old one.

Common breakdowns of popular brands of LCD TVs and how to fix them

Each manufacturer has its own weaknesses, so below is a selection of the most common breakdowns of LCD screens.

Philips TV repair

Often, users of this brand are faced with such a problem that when the device is turned on, it beeps without interruption. This symptom usually indicates that a leak has occurred. It is recommended that you try replacing the pre-output diode.

Another common problem is the monitor turning itself on and off. The main cause of this breakdown is a failed transistor, it is necessary to replace it. Such malfunctions are recommended to be eliminated independently only by people who have experience in repairing television equipment.

If the breakdown is complex, then it is better to entrust its elimination to specialists who will not only professionally perform repairs, but also issue a guarantee. Therefore, if the repaired screen stops working again, the user may demand a refund.

LG TV repair

Owners of LG flat screens may have trouble saving settings. Such a problem does not require an appeal to the masters; LG TV repair can be done independently. It is enough to transfer the device to another mode of operation, and all settings will be saved.

As well as in the case of other LCD models, if the problem is serious, then do-it-yourself LG TV repair is not recommended, it is better to contact specialists.

kinescope screens

Despite the fact that today most consumers prefer the most modern plasmas, kinescope screens are still in demand. These TVs have their advantages: they are inexpensive, easy to operate, and the quality of the transmitted picture is still high.

The main problems of kinescope devices:

• the kinescope TV does not turn on - just like on other types of devices, first of all, you need to check the integrity of the fuses;
• a malfunction of the diode bridge is a common problem for kinescope receivers, you can fix the TV only after performing a “ringing”, you will need a multimeter from the equipment;
• breakage of the thesistor - is considered the most serious problem, in order to check, you need to turn off the power supply circuit of the TV, then start it again. After, observe the lamp, if it goes out, it means that the posistor is out of order. First of all, you need to adjust the resistance of the network, and then replace the part;
• burnout of a transistor or capacitor - such a problem can be easily replaced by visual inspection (black carbon deposits on parts), repairs are carried out by replacing the part.

Typical malfunctions of kinescope equipment and methods for their elimination

Below is a list of problems that owners of kinescope TVs face.

1. TV Rubin hums loudly when connected - most likely, you need to replace the photodetector.
2. The ruby ​​does not turn on, the indicator does not light up - voltage surges in the transistor.

Horizon:

1. The Horizon TV does not have a blue tint, and the white balance is also off - this is mainly due to a broken resistor.
2. There is sound, there is no image - the cause of the problem is poor contact in the power connector of the screen board. It is recommended to use a soldering iron to solder the bundle into the Horizon TV board.

1. The screen does not turn on - the problem is with the power supply.
2. A horizontal strip appears on the monitor - repairing a TV hero consists in fixing a problem in the frame scan chip.

Power supply repair

Since the failure of the power supply is one of the most common problems of all types of TV, it is necessary to study it in more detail.

Repair of power supplies for LCD TVs

Since all models of LCD monitors do not have fundamentally different design differences, therefore, the diagram below can be applied to all TVs (Toshiba, Horizon, Samsung, Sony, Rubin).

Instruction:

1. Open with tools back case devices.
2. Having unscrewed the cover, the user will see the LCD TV power supply located on the left side, and the main board is on the right.
3. There are three transformers on the board of the unit: the lower, the upper and the transformer on the right side - it is responsible for the on-duty operation of the monitor, and you need to start checking from it.
4. The transformer responsible for the standby mode must provide a voltage of 5V. To understand which wire to measure, it is recommended to use the diagram or look at the case markings. Near the desired contact will be filled with -5V.
5. An open circuit is measured first, it is necessary to attach one probe to the -5V contact, and the other to the cathode of the diode located on the radiator. Put the tester in ringing mode, and check the circuit. Availability sound signal will indicate that there is no break.
6. Then attach one multimeter probe to the TV panel, and leave the other on the same contact, plug the screen into the network and measure the voltage. If the device shows a value less than 5V, for example, 1.5, then this indicates that the TV is not working at full capacity, the capacitor may have dried up.
7. It is necessary to re-solder the elements that have gone out of work, to do this, remove the board, disconnect the matrix cable.
8. After the work is done, the screen should turn on.

CRT TV

Repair of monitors equipped with a kinescope, for example, such as (ruby, sharp 2002sc, sony trinitron, vvk), as well as repair of Samsung TV, Panasonic. always starts checking the power supply.

Testing is performed using an incandescent lamp, but before performing the procedure, be sure to disconnect Sharp c2002sc, Samsung or another screen from the load (line scan cascade). The horizontal scanning voltage can vary from 110 to 150 V, it depends on the size of the kinescope. It is required to find a sweep filter capacitor in the TV circuit. Next, you will need to connect a light bulb, in order to remove the load, you need to unsolder the inductor and fuse through which the JV element consumes power. This scheme is used for sharp screens from 2002sc.

After, connect the power adapter to electricity and measure the voltage, if the values ​​\u200b\u200bare exceeding the norm, you will have to check the circuit feedback power supply. If the PSU is in good condition, then the light bulb is removed, and all the elements are soldered in place. This is basic information on how to repair a TV with your own hands.