In detail: do-it-yourself goldstar TV repair from a real master for the site my.housecope.com.
The TV does not turn on, the mains fuse F801 blows out Faulty elements of the input filter, demagnetization system, rectifier
Disconnect the rectifier (DB813) from the pin. 7 T802 and an ohmmeter to determine the location of the short circuit.
It should be noted that the demagnetization system will bypass the input circuits due to the low resistance in the cold state of the TN801, so it should also be turned off.
The elements of the converter on the IC802 are faulty
If the input circuits are working properly, it is necessary to evaporate IC802 and check the power transistor for a short circuit (pin 1 of IC802 - collector, pin 2 - emitter, pin 3 - base), damping circuit elements: C829, L803, as well as C829. Also check the serviceability of windings 1 - 3; 5 - 7 T802. If not, replace IC802.
The TV does not turn on, the mains fuse F801 is intact The power supply circuit of the power switch in IC802 is broken
Measure +300 V at pin. 1 IC802. If there is no voltage, check the circuit: F801, T801, DB813, vyv. 5 - 7 T802, L8045 L810, pin. 1 IC802.
The converter on IC802 does not work
Check winding 1 - 2 - 3 T802 for an open circuit, serviceability of the starting circuit on elements D814, R824, R825, as well as Q805, C826, D809, D810, C808, ZD811, C820, D816, D815, C825, R826. Otherwise replace IC802.
Faulty power channel +5 V standby (ST +5 V)
Measure voltage at IC04 input (+12 V) and output (+5 V). If there is no voltage, check R805, D812, D805, C830, FR812.
The TV does not switch to standby mode or from standby to operating mode
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Video (click to play). |
The elements may be faulty: Q801, Q802, Q804, IC803, IC801.
If the above elements are in good working order: check the receipt of the command to turn on / off the TV from the IC01 microcontroller (pin 22) - ON / OFF.
The TV does not turn on, a low-pitched sound is heard from the power supply
One of the secondary channels of the power supply is overloaded
Determine the overloaded channel with an ohmmeter and eliminate the cause of the overload. One of the secondary rectifiers of the power supply is faulty
Determine the faulty rectifier and eliminate the malfunction.
There is no picture or sound, the power supply is working (all output voltages are normal)
Check if there is a pin. 22 IC501 AXIS.
Check the serviceability of the elements of the line scan output stage (T401, Q401, Q402, etc.).
Check if the start of horizontal scanning is blocked by Q302.
The screen does not light up, the sound is normal
Check the following voltages: Unak, 11usk, 11high.
Adjust the BRI, CONT, set to the maximum position.
Check the serviceability of IC502, output video amplifiers Q901 - Q903 (check for the presence of R-Y, B-Y, G-Y signals at pin 19 - 21 of IC502 and the presence of R, G, B signals on the kinescope cathodes).
There is a raster, there is no sound or image (there is video noise on the screen)
Check the correct sampling of the sub-band (UB, HB, LB) by the microcontroller on the T181 tuner, whether the tuning voltage at the TU output of the tuner changes.
Check for AGC signal on the tuner (should be> 3V).
Check the health of the radio channel elements (T181, Q102, IC501).
There is an image, the sound is transmitted with strong distortion, wheezing
Check the correct operation of the cascades on Q203, Q204, Q205, as well as the serviceability of the filters: Z207, X601, Z604 - Z606.
Check the serviceability of the UMNCH IC601.
One or more buttons on the control panel do not work
Check the serviceability of the buttons with an ohmmeter.
Control with the remote control does not work Faulty elements of the remote control
Check the serviceability of the remote control batteries.
Press any key on the remote control, on the pin. 23 U01 must be pulses. If they are not there, check CF1, C2, SZ, replace U01. Next, check the serviceability of Q1, D1. Checking the remote control can be simplified by connecting any red LED in parallel with D1. At any pressed button of the remote control, the “blinking” of the external LED indicates the serviceability of the remote control (you will also need to check CF1).
Photodetector PA01 is faulty
If the remote control works, check PA01. On pin. 2 should have the same impulses as on the remote control. If not, replace PA01.
If the signals from the remote control come through PA01 to pin.15 IC01, and there is no processing of control commands, then check (better by replacing) X01, replace IC01.
The CRT screen glows in one of the primary colors, the reverse lines are visible
The video amplifier of the corresponding channel is faulty Check the faulty stage.
Check successively by replacing.
Color image is missing
Set the COLOR control to the maximum value. If there is no color, then replace IC501, IC502 accordingly.
Color image is missing
When receiving one of the systems: PAL (1), NTSC (2), SEC AM (3)
In the first and second cases, check the health of the cascades on Q503, Q501, Q502.
In the third case, replace the IC502.
There is no frame (1) or line (2) sync
In the first case, check for the presence of CSI on IC501 (pin 30). If there are pulses and synchronization has not been restored, replace IC301.
In the second case, replace IC501.
Horizontal bar on the screen
Check the supply of voltages +9 V; +25 V on IC301.
Check the following items: SW301, V-DY, R317, C307, SZOZ, D301, C304. Replace IC301.
Vertical bar on screen
Check the lowercase OS circuits: H-DY, L402, C420.
Check the quality of the soldering of the elements along the circuit: collector Q402, H-DY, L402, C420; frame.
Image size is not adjusted vertically
Open in the feedback circuit IC301
Check VR301, R303, C304, R306. Replace IC301.
No sync when OSD is displayed
Check the signal formation circuits H-SYNC1, V-SYNC1 and their arrival at IC01 (pin 1.2).
If signals on IC01 are present, replace IC01.
No OSD backlight or one of the primary colors is missing when the menu is displayed
Check the primary color display circuits: IC01 (pin 52 - R; pin 51 - G; pin 50 - B), Q04 - Q02; pin. 22 - 24 IC502. Also check the V-MUTE signal path (pin 49 IC01), Q512, Q507, etc. If signals are present but display is not present, replace IC502.
No sound and / or picture from LF input / output
Check if the control signal from IC01 AV / TV comes to the pin. 2 IC201.
Check if IC201 is working properly. Check the serviceability of Q201, Q602.
There is a patient diagnosed with a large voltage surge from the network.
When turned on, only a high silk is heard, and then silence, the control lamp does not shine (standby mode)
Conder 220 mf at 400V exploded in the Pulse PSU. Conder replaced the result with the same one, all the resistors were all covered, all the diodes were whole.
But the current does not go through the transformer, that is, it does not reach the logic +5.
Added by (14.11.2014, 02:20)
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There is no cliff, no where, it doesn’t vanish. 
1678.) LG CF-21D70 (Chassis MS-64A) - in the bowl. the mode turns on. When switched to operating mode, there is a very loud and spectacular "shooting" in the TDKS. Sparks fly in all directions. The TDKS type 6174Z-8004B is faulty. Its cost is $ 18-22. On the schematic diagram of the MS-64A chassis, the TDKS 154-375F type is indicated for the 21 ″ diagonal, the cost of which is $ 8.5. I installed the 154-375F without any structural changes. TV started working. Geometry is OK. Configured SCREEN and FOCUS and that's it. But there is a drawback - the screen is rather blue with blue lines arr. course. As a result of the shooting of the line transformer, Q514, Q513 and Q512 (2SA1266Y) in the video amplifier failed. (Instead of 6174Z-8004B, another LG CF-21D70 TV was 154-375E. Sellers also offer 154-194D ($ 10) and HR7906 analogs.)
1679.) LG Cf-21d70 (Shasi Mc-64a) - When pressed on the button "Merezhu" indicator dij. sleep modeє for 2-3 sec. and go out. Stress from the power supply unit when pressed on the button "Merezhu", the nominal value for 1sec, then the stench smoothly changes to 0v for 1-2 seconds. in dіzh. mode). The button "Merezha" is correct, as a gift on the TB without the docks on it embossed by hand. Dear TB, having said that TB mayzhe start a buv in dіzh. modes, i.e. with a fancy button, they were crimsoning.
1683.) GOLDSTAR Cf-21e20b shasi MS-41... Incomparability of the titles, as you want to flash at the bottom of the frame, to double, so it is uncomfortable to read them, the picture itself is in a normal manner. I turn on the generator of the viprobular signals, I turn on the grid on the video input, everything is fine, but on the HF through the antenna you can clearly see a strong repetition of vertical lines, it is clear that there is an inequality in the radio channels. Vreshti-resht the inequality of the ball was localized in the filter surfactant K2559, replacing it with K2550.
1703.) Goldstar Cf-20f60. The TV set immediately turns on in the working mode, having passed the working mode. The frustration of the BP is envied. Invalid optocoupler Ic801.
1726.) Goldstar Cf-21c22x shasi Mc46a Living block at Strs6707. In the working mode of TB, work without respect, even when shifting the TB to St-by mode, the dynamics are sensitive to the clatter, the frequency and the clatter of the clatter can be reduced, after an hour or so, in time with the sound of repair, start the TDKS. Svitlodiod to light up normally .. Having made a mistake in the power supply unit in a row in the St-by, having seen all 80 volts, and the blame for the 40 volts, the axis along the whole and there were third-party sounds in the St-by. Invalid capacitor in the power supply unit, 10mkf per 100volt at the secondary lancet, for the optocoupler control.
1729.) LG Kf-21p10 When the big screen is on, the whole screen is going to change, the Tda6108 and the stabilizer for 5 noses (IK) 7V5 are invalid.
1746.) LG Cf-21f30k shasi MS 019a The living unit does not start: replacing the row transistor Tt2140 with 2SD2499 and TDKS 6174z-6040c (the defect of Tdks made on 09-10.2003 r.).
1804.) Goldstar CF-14/20 / 21A80Y... Fault: the buttons on the TV panel do not work properly. The volume is adjusted 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 microcircuit with firmware from a faulty microcircuit, the panel buttons again stop working. But the old firmware is not required.
1805.) Goldstar CF-14/20 / 21A80Y... Fault: in SECAM - the predominance of red, in PAL it is normal. Break off the capacitor built into the L502 circuit, hang in 100 pF. In my case, it didn't even need to adjust the contour
1820.) 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 work 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 microcircuit. In the absence of this signal, the sound is muted, the sound control output of the processor is set to a level corresponding to the minimum volume. The Q06 transistor (type KT315, it was this transistor that was installed during the previous repair) in the sync pulse data circuit was faulty. Who repaired Soviet TVs in large quantities knows this feature of the KT315.
1828.) LG-CF 20F39 Fault: vertical line. Breakage of capacitance 0.364 microfarad per 400V in a line. Capacitor manufacturer - WOO YANG
1833.) 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 microcircuit and the Q810 C3198Y power stabilizer transistor with a zener diode in the base did nothing. A careful analysis revealed a capacitor with an underestimated capacity C824 4.7 × 50v. After replacing the capacitor, the unit starts up. By the way, in earlier releases of these models there was a 220.0 × 5v capacitor, there were no problems.
1848.) LG CT-20T30KE Fault: After a while, it starts to lose 1 channel or all at once. The vertical size may jerk. Can switch off to the duty room. Can cease to be controlled. The sound disappears. Line scan disappears for a short time, etc. Replacing the memory (you can put a clean one) and quartz, - did not work. Replacing the TDA9381PSN23 / 0701 processor. When installing processors with other firmware, the TV does not come out of standby mode, while changing the firmware in the memory chip as it pleases.
1849.) LG Ct-20t30ke Incomparability: Nemaє color LIG. Replacement quartz 12.000 MHz. Quartz, new, may not meet the tolerance.
1859.) Goldstar CF-14/20/21 / E20B (MC-41B)... Fault: in SECAM it turns red, sometimes it works fine. Condenser on the pin. 26 of the AN5633 transcoder, check the replacement.
1899.) LG CT-20T30KE... Replacing the TDA9381PS / N2 / 3/0701 (OICTMPH007B) processor with the TDA9381PS / N2 / 3I0792 (OICTMPH010A). Everything is okay. Only the raster is slightly shifted vertically downward. I had to look for an entrance to the service. 2 OK buttons on the remote control and the 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 not in the bowl
1959.) LG, chassis MC-41B... MV is working fine, the setting is leaving the UHF. Configuring the APCG circuit gave nothing. During measurements, it was noticed that the TU on the tuner on the UHF range does not change smoothly when tuning, but “jumps”. The defect is in the tuner.
1975.) Goldstar (LG) 21d16cf, 20a80y low intensity of LIG, sekam norm, replacement of microcontroller Gs8334-09c
1977.) Goldstar GF20D60B PSU (STRS 6707) does not start, LED lights up for a second and goes out, chassis MS-1V breakdown of the zener diode ZD811
1997.) LG CT-21Q42KEX chassis MC-019A The power supply does not start, the F801 fuse burns out, upon examination, it found a burnt out diode bridge DB801 D2SB and a capacitor C801 1000p 1kV after replacing the defective parts, the TV worked.
2011.) GoldStar CF-21A80Y and other similar models. ATTENTION. When working with a power supply unit on the STR-S6707 microcircuit, be sure to discharge the storage capacity 220x400V.
Fault: when the network is turned on, the standby indicator starts blinking frequently. The capacity of C826 220.0x35v in the Q805 KTD2092 circuit is faulty.
Fault: low brightness. When you add brightness accelerating with TDKS, the frame stops working: a narrow band. The 9v stabilizer turned out to be faulty: power supply for 1 leg of the personnel microcircuit.
Fault: the 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 2-2.5 times. A similar malfunction must be sought in the stabilization device. In this case, the faulty resistor R814 (12kΩ) in the LED circuit of the IC801 optocoupler.
2019.) GoldStar 9322B (chassis PC-05X2) when turned on, it floods with milk, the brightness and contrast adjustments do not affect, I suspended the 8th leg of the TDA3562A video processor (analogue of KR1024XA4) through 1 Megohm to +, the image began to peep slightly. Replacing the microcircuit did not give anything. The transistors on the CRT board rang - everything is ok! I decided to replace the Q907 2SA1015 transistor, the tester rings normally. After the replacement, the TV worked.
2021.) LG CF-20F39... Fault: no picture. There is a vertical bar on the screen. The capacitor in the chain of line coils is faulty (it seems C412) with a nominal value of 0.36 μFx400 V - open circuit. You will never think about the appearance.
2046.) LG CF21D30 chassis MC-64B after replacing TDKS, burnt out R424 10kom, punched out by D401. Fault: the TV starts up and after a few seconds goes into standby mode. Each subsequent switching on from the remote control reduces the operating time. As a result, there was a broken Q302 transistor, which gives an ABNORMAL impulse to the 20th leg of the processor.
2093.) LG-CF21F60K, processor TDA 9381 PS / №2 / 3/0533 Fault: white inclined stripes on a dark screen, when the antenna is turned off, light snow appears. According to the hostess, the image disappeared when the video camera was connected to N.Ch.'s low-frequency input. Connecting 42 legs of the processor (external video input) through a resistance of 1 ohm to ground - restored the TV operation on V.Ch. and according to N.Ch.
2104.) GoldStar CF-14A80Y, CF-20A80Y, CF-21A80Y Chassis MC-41A... Central processor IC01 GS8334-09A (GS8334-09C) Fault: There is no sound in TV mode, there is in AV mode. During tuning to the channels, it does not stop (skips stations). The leak is Q06 2SC3198.
2112.) GOLDSTAR CF20E20B Fault: there is no picture and sound. On examination, I found out that there is no power supply to the TA8690 video processor. The reason - the stabilizer IC402 (KIA7809) is out of order. After replacing the microcircuit, the TV worked.
2144.) GOLDSTAR CF20A80 Fault: it turns on on any random program, when you press the program switch button, a menu pops up, etc. Replace 24CO2 memory.
2152.) LG Cf-21f30 Incomparability: no launch. Living block at Strs5707. Visoh S824 4.7x50v
2153.) LG-21D33 (chassis MS-84A) Fault: after 1-1.5 hours of operation, the TV periodically turns off into 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 Reset circuit IC03 KA7542 turned out to be faulty.
2185.) GOLDSTAR CK21A90 Fault: does not turn on (shortly before the breakdown, it turned on once). The power supply is cut off (1.5 mOhm is ringing) R802 680 com.
2191.) LG CT-25Q20RQ Fault: does not turn on, the standby indicator is off. At the break of R830 (like a resistor-fuse, a 0.47 ohm resistor is installed instead of it), it is in the secondary, +12 volts are supplied through it.
2196.) Gold Star CF-29C44 MS-51A chassis. 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, plowed everything up. And all because you have not read "The Secrets of Repair". Thanks to Boris Bokachev
see secret 450. The repair took 15 minutes.Of these, 10 minutes I searched for the position number IC7P (very inconspicuous) on the PIP board - KRENK 78L08. When measured at the moment of switching on, 4v appeared at its output instead of 8v. After replacing it, everything worked.
2203.) LG CF-21J50K, CT-21Q41KE chassis MC 019A Fault: the power supply unit does not start (taps). Replacing the TT2140 line transistor with 2SD2499 and TDKS 6174Z-6040C analog of HR8656 (if there is a short circuit across all the terminals of the line transistor, TDKS will probably have to be changed, there is a marriage of TDKS made on 09-11.2003) in my practice there are three LG TVs of Russian assembly of different brands , but with the same chassis, all multipliers “died”, and the windings are intact. And the TVs are still under warranty.
2204.) LG CT-29K30VE chassis MC 022A Fault: there is no image and raster (the 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 a detailed check of the strapping, the D903 diode on the CRT board turned out to be blue in color, after replacing it with ours from MC-2 (there was no native one) the image appeared.
2213.) LG RT-21FA32X Fault: the TV does not turn on from standby mode. It turned out to be faulty C820 200.0x160.
2259.) Goldstar Cf-20e20 (block of living of zibraniy on Str-s5707). Incomparability: to turn on the TV from a cold start, it is necessary to press 10-15 times the button to be pressed. For usuneniya inequities, it is necessary to replace two capacities: C820 and C825, both 220.0x35v.
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Steve Jobs. 1955-2011. We remember how you transformed our world.
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Steve Jobs. 1955-2011. We remember how you transformed our world.
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Steve Jobs. 1955-2011. We remember how you transformed our world.
_________________
Steve Jobs. 1955-2011. We remember how you transformed our world.
_________________
Steve Jobs. 1955-2011. We remember how you transformed our world.
_________________
Steve Jobs. 1955-2011. We remember how you transformed our world.
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Steve Jobs. 1955-2011. We remember how you transformed our world.
They say that if the condenser in the switching power supply module stands, after the power, rectifying diodes, then it is like:
-as an anti-aliasing,
and increasing the voltage of 300-350 volts.
-Just how does he do it?
_________________
Steve Jobs. 1955-2011. We remember how you transformed our world.
_________________
Steve Jobs. 1955-2011. We remember how you transformed our world.
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It is no secret that a breakdown of a television receiver can ruin the mood of any owner. The question arises, where to look for a good master, do you need to take the device to a service center? You need to spend your time on this, and what is important - money. But, before calling the master, if you have basic knowledge of electrical engineering and know how to hold a screwdriver and a soldering iron in your hands, then repairing the TV with your own hands in some cases is still possible.
Modern LCD TVs have become more compact and easier to repair. Of course, there are breakdowns that are difficult to detect without special diagnostic equipment. But most often there are malfunctions that can be detected even visually, for example, swollen capacitors... With such a breakdown, it is enough to evaporate them and replace them with new ones with the same parameters.
All TV sets are the same in their structure and consist of a power supply unit (PSU), a motherboard and an LCD backlight module (lamps are used) or LED (LEDs are used). It is not worth repairing the motherboard on your own, but the power supply unit and screen backlight lamps are quite possible.
As already mentioned, the design and principle of operation of LED and LCD TVs, regardless of the manufacturer, are the same. Of course, there are some differences, but they do not play a significant role in the diagnosis of faults. Often, in the event of a problem with the power supply, the LCD TV does not turn on at all, while there is no indication, or it turns on for a while and turns off spontaneously. Using an example, the repair of a DAEWOO LCD power supply unit (can be applied to plasma) is considered, which is not much different from repairing an LG TV, as well as Toshiba, Sonya, Rubin, Horizon and similar models.
- First of all, before you repair the TV, you need to remove the back panel of the device with a screwdriver by unscrewing the screws. On some models, the rear wall may be latches installedwhich must be handled with care so as not to break them.
- After removing the cover, you will see the power supply unit, consisting of several modules on the left, and the motherboard on the right.
- On the power supply board you can see 3 transformers: the bottom one is the mains rectifier choke, the top one on the left (large) feeds the inverter, and on the right is the standby power supply transformer. You need to start checking with it, since it turns on the standby mode of the TV receiver.
- Duty transformer when the device is connected to the network, it should give out a voltage of 5 V. In order to correctly find the wire on which you need to measure the voltage, you can use the diagram, or you can see the markings on the case. In this case, opposite the desired contact is written - 5 V.
Measurement is taken first open circuitby connecting one probe to the found contact, and the other to the cathode of the diode on the radiator. In this case, there is no break. 
As you can see from the review presented above, repairing TV power supplies with your own hands is not such an overwhelming task. Following this description, you can also repair plasma TVs.
Do-it-yourself TV repair with a kinescope, for example, such as: Rubin, Horizon, Sharp 2002sc, LG TVs, as well as repair of the Vityaz TV, begins with checking the power supply unit for operability (this is done if the unit does not turn on). It is checked using incandescent bulbs for 220 V and a power of 60-100 W. But before that, be sure to disconnect the load, namely the horizontal output stage (SR) - connect a lamp instead. The CP voltage ranges from 110 to 150 V, depending on the size of the tube. Must be found in the secondary circuit SR filter capacitor (its values can be from 47 to 220 microfarads and 160 - 200 V), which stands behind the SR power rectifier.
To simulate the load, you need to connect a lamp in parallel to it.To remove the load, for example, in the popular Sharp 2002sc model, it is necessary to find and unsolder the inductor (located after the capacitor), the fuse and the limiting resistance through which the CP stage receives power.
Now you need to connect the power supply to the power supply unit, and measure the voltage under load. The voltage should be between 110 and 130 V if the CRT has a diagonal of 21 to 25 inches (as in the 2002sc model). With a diagonal of 25-29 inches - 130-150 V, respectively. If the values are too high, then it will be necessary to check the feedback circuit and the power supply circuit (primary).
It should be noted that electrolytes dry out and lose capacity during prolonged operation, which, in turn, affects the stability of the module and contributes to an increase in voltage.
When the voltage is too low it is necessary to test the secondary circuits to exclude leaks and short circuits. After that, the diodes for the protection of the power supply of the SR and the diodes for the power supply of the vertical scan are checked. If you are convinced that the power supply unit is working properly, then you need to disconnect the lamp and solder all the parts back. This check can also come in handy when doing DIY Philips TV repairs.
Another common breakdown of the TV that can be eliminated is the burnout of the backlight lamp. In this case, the TV receiver, after switching on, flashes the indicator several times and does not turn on... This means that after self-diagnosis, the device notices a malfunction, after which the protection is triggered. That is why there is no image on the screen.
For example, a Sharp LSD TV receiver with this malfunction was taken, although in this way it is possible to repair Samsung TVs, Sony Trinitron, Rubin, Horizon, etc.
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To fix the TV, you need to remove the back panel from the TV. This requires a screwdriver or screwdriver.
Next, you need to be careful disconnect loops from the matrix. 
Thus, you can repair the Philips and LG TV with your own hands, and other LCD panels, as well as devices with LED backlight (LED). Owners of the latter type of devices should read the article on repairing LED backlighting, where the whole process is described in detail using the example of an LG TV.
Among the typical and simple reasons that the TV set does not turn on, there may be a remote control or a lack of signal from the antenna cable.
If the TV does not turn on with the remote control, first, you need to make sure the batteries are good. If they are shrunken, replace them. Often the TV set cannot turn on due to contamination of contacts under the buttons. To do this, you can disassemble it yourself, and clean the contacts with a soft cloth from accumulated dirt. If your remote control has been dropped, it is possible damage to the quartz emitter... In this case, it must be replaced. Well, if you filled the remote control with water or some other liquid, and it did not work after disassembling and drying, then it will have to be replaced with a new one.
You can learn more about fixing the remote control in the following video or article.
When repairing TVs LG, Sharp with LCD, Rubin, Horizon with the same screens, a situation often arises when it does not turn on when the device is in good working order. It turns out that the reason may be no TV signal in the antenna cable. This happens due to the operation of the noise suppression protection (in Rubin TVs, they began to install it not so long ago), and the unit goes into standby mode. Therefore, if you find your TV set in an inoperative state, you should not panic, but you need to check the presence of a signal from the transmitting station.
In conclusion, we can say that when you decide to repair a TV set yourself, you should soberly assess your abilities and knowledge in this matter. If you do not feel confident, then it is better to entrust this matter to a telemaster, especially since nobody canceled 220 V, and ignorance of basic safety rules can entail unpleasant consequences.
Do-it-yourself TV repair is a responsible business, since today a large number of different models (LCD, LSD, CRT) are presented 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 are:
- TV screen does not turn on - this can happen with an old picture tube screen and with the most modern television panel. Basically, this symptom is characteristic of a blown fuse. When repairing, it should be borne in mind that the appropriate fuse must be selected for each model. 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 what to do if Samsung TV does not turn on.
- Faint, barely noticeable picture - this kind of breakdown happens with LCD / LCD monitors. The most likely cause of the malfunction: faulty diodes, device backlighting.
- There is no sound, the screen "wheezes" - most likely, the sound amplifier or microcircuit is out of order. Also read what to do if there is sound, but there is no picture.
- Monitor is on, 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 rupture of elements is detected during a visual inspection of television equipment, then it is not recommended to immediately start replacing parts. Since such factors indicate a short circuit that could have occurred in another section 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 itself.
To repair television equipment, the following tools and equipment may be required:
- Screwdriver Set;
- hex keys (in rare cases);
- pliers;
- soldering station (for repairing modern monitors);
- screen layout (can be downloaded on the Internet);
- multimeter;
- oscilloscope.
Many LCD screen problems can be dealt with on your own. But you should know 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 start repairing the LCD or LED screen. You should know that LCD TVs use fluorescent bulbs for backlighting, while LEDs use LEDs.
The TV may not function due to lack of power, to check this, you need to do the following:
- Open the back cover of the LCD TV with tools.
- Disconnect the wires that are connected to the device matrix.
- Connect a working light bulb to the contacts.
- Some panels have more than one light source, in which case they must be tested as well. This can be done 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 the faulty luminaire is found, it must be replaced. This procedure should be carried out as carefully as possible. In most cases, the lamp can be taken out even without removing the matrix - you need to move the protection elements aside and take out the burned-out 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.
Another common problem with these models is damage to the monitor. But in this case, it is not advisable to repair LCD TVs, since it is easier to buy a new screen. This test scheme can also be used to repair plasma televisions of all types. Read also how to fix the LED backlight yourself.
Each manufacturer has its own weak points, so below is a selection of the most common LCD screen breakdowns.
Often, users of this brand are faced with such a problem that when turned on, the device beeps without interruption. This symptom usually indicates that a leak has occurred. It is recommended to try replacing the preout stage diode.
Another common problem is that the monitor turns on and off itself. The main reason for this breakdown is a failed transistor, it is necessary to replace it. It is recommended that such malfunctions be eliminated on their own only by people who have experience in repairing television equipment.
DIY Philips TV repair is recommended if the problem is minor: settings are lost, cable replacement is required.
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 flat screen owners may have a problem saving settings. Such a problem does not require contacting the masters; you can repair your LG TV yourself. It is enough to switch the device to another operating mode, and all settings will be saved.
As well as in the case of other LCD models, if the problem is serious, then it is not recommended to repair an LG TV with your own hands, it is better to contact a specialist.
Despite the fact that today most consumers prefer the most modern plasmas, CRT 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 with CRT devices:
- the CRT TV does not turn on - just like on devices of a different type, first of all, you need to check the integrity of the fuses;
- a diode bridge malfunction is a common problem with CRT receivers, you can fix the TV only after making a "ringing", you will need a multimeter from the equipment;
- breakdown of the posistor is considered the most serious problem; in order to check, it is necessary to turn off the TV's power circuit, 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 malfunction can be easily replaced by visual inspection (on black carbon parts), repair is carried out by replacing the part.
Below is a list of problems encountered by owners of CRT TVs.
- The Rubin TV buzzes loudly when connected - most likely, the photodetector needs to be replaced.
- The ruby does not turn on, the indicator does not light up - voltage surges in the transistor.
- The Horizon TV does not have a blue tint, as well as the white balance is disturbed - this is mainly due to a broken resistor.
- There is sound, no image - the cause of the problem lies in poor contact of the power connector of the screen board. It is recommended to use a soldering iron to solder the harness into the Horizon TV board.
- The screen does not turn on - there is a problem with the power supply.
- A horizontal strip appears on the monitor - repairing a Vityaz TV consists in fixing a problem in the frame scan microcircuit.
Since the malfunction of the power supply is one of the most common problems of all types of TVs, it is necessary to study it in more detail.
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).
Repair of monitors equipped with a picture tube, 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 carried out using an incandescent lamp, but before performing the procedure, it is necessary to disconnect Sharp c2002sc, Samsung or another screen from the load (horizontal cascade). The horizontal scan voltage can vary from 110 to 150 V, it depends on the size of the picture tube. 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, it is necessary to unsolder the choke and the fuse through which the JV element consumes power. This scheme is used for sharp screens since 2002sc.
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After that, connect the power adapter to electricity and measure the voltage, if the values exceed the norm, you will have to check the feedback circuit of the power supply. If the power supply unit is in good condition, then the light bulb is removed and all the elements are soldered into place. This is the basic information on how to repair a TV yourself.
