Samsung TV backlight does not work

Samsung TV backlight does not work

Telebalt LLC produces TVs of the following brands today: Erisson, Hitachi, Hyundai, JVC, Panasonic, Philips, Samsung. This material has been prepared on the basis of the experience of pre-trade and warranty repair of Samsung TVs manufactured by Telebalt LLC, made on the chassis KS7C, KS9A, S16A / B / C / D, S61A, S65A, KSBA. In addition, the authors used the materials of the forum on the MONITOR website. The first article will address malfunctions of Samsung TVs made on the S16A / B / C / D chassis.

Matching model. the chassis of Samsung TVs manufactured by Telebalt LLC is presented in table. one.

Chassis KS7A / C Chassis KS9A Chassis S16А / B / C / D Chassis S61A Chassis S65A Chassis KSBA
CS-15K2MJQ CS-21M20MQQ CS-21M16ZAQ CS-25M20SSQ CS-29Z30HPQ CS-21Z43ZGUSNWT
CS-15K8MJQ CS-21M21MQQ CS-21M20ZQQ CS-25M6SQQ CS-29Z30HSQ CS-21Z43ZGUXNWT
CS-21K30F1Q CS-21N11F1Q CS-21M21ZAQ CS-29A11SSQ CS-29Z40HPQ CS-21Z45ZGUSNWT
CS-21K30MJQ CS-21N11MJQ CS-21M21ZQQ CS-29M20SPQ CS-29Z40HSQ CS-21Z45ZGUXNWT
CS-21M16MAQ CS-21Z30ZAQ CS-29M20SSQ CS-29Z45HPQ CS-21Z47ZGUSNWT
CS-25M20MQQ CS-21Z30ZQQ CS-29M21SQQ CS-29Z45HSQ CS-21Z47ZGUXNWT
CS-25M20ZQQ CS-21Z40ZAQ CS-29M6SQQ CS-29Z47HPQ
CS-25M6MAQ CS-21Z40ZQQ CS-29Z47HSQ
CS-25M6ZAQ CS-21Z45ZQQ CS-29Z50HKQ
CS-29K10MAQ CS-21Z47ZQQ CS-29Z50HPQ
CS-29K10ZAQ CS-21Z50ZQQ CS-29Z50HSQ
CS-29M20ZAQ CS-21Z57ZQQ CS-29Z57HPQ
CS-29Z30ZQQ CS-25M20ZQQ
CS-29Z40ZQQ CS29K3ZQQ
CS-29Z45ZQQ CS-29K5ZQQ
CS-29Z50ZQQ CS-29K30ZQSNWT

The basic composition of the S16A / B / C / D chassis is shown in table. 2.

Typical malfunctions of Samsung TVs on the S16A / B / C / D chassis

Faults in the switching power supply (UPS) and line scan (CP)

The UPS does not start up One of the Zener diodes D814, 813, 816, 815 is faulty (breakdown) or the STRW6750F microcircuit is faulty.

Unstable start of the UPS (sometimes it does not start) Intermittent breakage of diode D803 on power supply STRW6750F.

TV does not turn on, UPS is working normally Zener diode DZ510 (5V) is faulty.

TV does not turn on, all output voltages are underestimated by half Open resistor R921 in the RESET circuit.

TV turns on for 1sec (all secondary voltages appear at the UPS output) and turns off 1 STRW6750 controller there is only 310 V, and on the pin. 4 power “pulsates”. Replacing STRW6750, checking electrolytic capacitors, zener diodes and short circuits in secondary circuits did not solve the problem. When checking the UPS in stand-alone mode (instead of line scan, it was loaded with a 220 V / 60 W lamp), the malfunction manifested itself in the same way. Cause. the value of the resistor R821 has increased (123 kOhm, it is in the power supply circuit of the DZ805 zener diode) to 200 kOhm.

TV does not turn on When the UPS is loaded with a lamp (220 V / 60 W) along circuit B, the 12 V bus on the board to the pin burns out. IC802 (78RM33). The 125 V supply voltage appears and disappears immediately. Cause. IC802 is faulty or the resistor R836 is shorted to the IC802 radiator.

TV does not turn on. When the UPS is loaded with a lamp (220 V / 60 W) along the B circuit, it flickers weakly, the voltage on the B bus varies from 0 to 20 V TPI (T801S) is faulty

TV does not turn on, UPS output voltages correspond to standby mode of operation. Possible causes:. The voltage of 3.3 V at the output of the regulator IC802 (78RM33) is 2.9 V. Cause. poor-quality soldering of the capacitor C905;. breakage of the output of the quartz resonator X201;. pin. 5 of the IC902 EEPROM memory chip is shorted to the pin. 6 (SDA and SCL buses) In all three cases, due to the above reasons, the IC201S microcontroller does not work, therefore the UPS is in standby mode.

TV does not turn on, the supply voltage of the CP 125 V is too low to 80 V The transistor Q903 is not installed (factory defect) or a short circuit on the board between the collector Q902 and C921.

TV does not turn on, all supply voltages are normal The microcontroller IC201S (TDA12025PQ / N1F80) is faulty.

After switching on, the image is absent, a “squeak” is heard, “swelling” of the capacitor C506 on the CRT board (PC) The polarity of the capacitor C506 is reversed (factory defect).

TV does not turn on, UPS protection is activated (the power supply goes into operation when there is a short circuit in the load) When checking without soldering, the CP Q401 output transistor is determined as faulty. Cause. short circuit of the SOC and KOK terminals in the installation and, as a consequence. malfunction of the microcircuit KR IC301.

TV does not turn on, protection is triggered Defective (broken) horizontal output transistor Q401. After replacing the transistor and turning on the TV, the UPS “pokes” three times, the sound from it turns into a whistle, the Q401 transistor heats up and fails again, and the C403 capacitor (1μF x 160 V) heats up and swells. Checking supply voltages, replacing TDKS and OS did not help. Cause. malfunction IC903 (KA78R08): the output voltage is underestimated to 2 V instead of 8 V. The defect is typical, quite often the port for connecting the local keyboard and the IR receiver RM901 is damaged (no response to buttons and remote control).

Sometimes the described damage to the local keyboard connection port (pin 15 pin of the IC201S microcontroller) manifests itself as a mismatch between the key functions and the functions indicated on the front panel of the TV. At the same time, control from the remote control is fully preserved. By mutual agreement of the client and the master, the microcontroller (due to the cost and limited availability) may not be replaced.

In the absence of a controlled stabilizer microcircuit KA78R08 (IC903), you can assemble its analogue on discrete elements according to the diagram below (see Fig. 5):

Fig. 5. Analogue of the controlled stabilizer KA78R08 on discrete elements

The TV does not turn on, the LED on the front panel of the LD901 does not light up The IC201S microcontroller (TDA12025PQ / N1F80) is faulty, on its power bus instead of 3.3 V. 2.7 2.9 V. The remaining supply voltages corresponding to the standby mode were also underestimated: instead of 90 V 86 V, instead of 12V. 6 V, instead of 5 V. 4.5 V.

TV does not turn on in operating mode In standby mode, voltage V is 140 V. When checking the UPS in stand-alone mode (instead of line scan, incandescent lamp 220 V x 100 W), voltage V is 113 V. When trying to turn on in operating mode, the voltage “sags” up to 97 V, a sound similar to “crunching” is heard from the UPS, the LED on the front panel blinks 5 times, and on the pin. 73 IC201S (H-OUT) CP trigger pulses appear and disappear. Cause. faulty TDKS.

TV does not turn on, protection is activated There is no 3.3 V supply voltage due to a malfunction of the IC201S microcontroller. nutritional breakdown.

The TV may not turn on, if it turns on, then the on-screen menu periodically appears and disappears on the screen Broken conductor about 3 pins IC901 (3.3V).

TV does not turn on, UPS restarts (“ticking” sound) Diode D404 (DGP30L) and transistor Q404 (FQP630) are faulty. After replacing them, TV started working, but Q404 heats up strongly, while geometric distortions of the raster are not observed. Strong heating of the above transistor is typical for this chassis, however, after replacing the L405 (1 mH), the heating decreased to acceptable limits.

No raster, no high (anode) voltage, voltage B is too high Open primary winding TDKS T444S (FOK 14A001), visually detected swelling of its case.

When the TV is turned on, it goes into working mode, but the image appears at a constant frequency of about 7-10 seconds for 1-2 seconds The image is stretched vertically and narrowed horizontally (about 10% of the nominal size). The color and sound are normal. The client associates the appearance of a malfunction with a thunderstorm preceding it.

The UPS was tested in stand-alone mode using an incandescent lamp. When a 220 V / 60 W lamp was connected to it instead of a horizontal scan, there was no voltage at the UPS output. When the lamp power decreases to 25 W, voltage B appears and disappears with a frequency of 1-2 Hz, its value is about 20 V. During the check, an interesting feature was found. if you first turn on the UPS, and after 2-3 seconds connect the lamp (25-60 W), then voltages appear at the output of the UPS that fully comply with the norm. For some UPSs used on other TV chassis, this is the norm, as it is perceived by the protection circuits as an overcurrent. However, this UPS should start confidently in stand-alone mode with an incandescent lamp with a power of up to 100 watts. In this case, the voltage in standby mode should be 117 V, and in working mode. 125V.

The cause of the malfunction. controller IC801S (KA5Q0765R). It should be noted that this behavior of the UPS can also be caused by a malfunction of the secondary voltage stabilization circuits.

When the TV is turned on, the LD901 LED flashes continuously with reduced brightness Breakage of the Q903 (A539) transistor installed in the 1.8 V power supply circuit (pin 90 IC201S).

TV does not turn on, LED LD901 is constantly blinking Jumper is not soldered in the CP supply voltage circuit from the UPS to the CP Q401 output transistor (factory defect).

LED LD901 is constantly on Track break from pin. 54 IC201S to R920.

LED LD901 does not light up, TV is working normally QV901 transistor is not installed, there is no jumper in pos. 144 (manufacturing defect).

TV does not turn on, LED LD901 does not light Open circuit of the choke L909 in the 3.3 V supply circuit.

TV turns on, pulses of starting the SR appear on the pin. 73 IC201S and immediately disappear, after a while the process is repeated Breakdown of the diode D409 in the OS circuit.

On the TV screen, there are “rainbow” stains, no KR Opening of the resistor R305 (connected to pin 7 of IC301).

TV turns on, “rainbow stains” are observed on the screen, resembling the throat of a CRT, the raster is gray One of the power supplies of the KR microcircuit is missing. If the TV is kept on for a long time, then the kinescope can be damaged (according to statistics, the neck of the kinescope may collapse).

No frame scan Breakdown of the Zener diode DZ301.

The raster is narrowed vertically. The KR microcircuit is in good order, the SR supply voltage is normal. Cause. poor-quality soldering of the capacitor C410 (470 μF x 25 V).

After 10 minutes of operation, the vertical size decreases Faulty microcircuit KR LA78045 (40).

After a few minutes of operation, the vertical size decreases symmetrically. Overheating of the KR microcircuit due to poor contact with the radiator.

Chaotic change of the vertical size (“breathing” of the raster) The appearance of turn-to-turn closure in the COC.

Inversion of the raster vertically in the upper part In position C302, a capacitor with a capacity of 1000 pF instead of 10 pF.

Three colored mowing lines are visible on the dark screen in the middle. When the accelerating voltage is increased by the Screen regulator on the TDKS, the backward mowing line of the SR becomes visible on the screen, the shape of the launching pulse of the KR is distorted Breakdown of the Zener diodes DZ302, DZ303, DZ306.

The image is compressed at the bottom and with a strip of “knocked-out” lines in the upper part The capacitor C303 is not installed in the.16.5 V circuit.

There is a narrow horizontal strip on the screen, limited at the edges Poor soldering of the resistor R414.

There is no frame synchronization in the LF input mode IC201 is defective (TDA12025PQ / N1F80).

Malfunctions associated with the distortion of information in the EEPROM

TV does not turn on. There is no POWER signal from the pin. 6 IC201S 6 IC201S high potential (3.3V) is always present. Cause. distortion of information in EEPROM.

OX mowing line is visible on the screen, adjusting the accelerating voltage does not affect the image Information in the EEPROM is distorted.

No sound in LF input mode Information distortion in EEPROM.

The TV is working, the UPS voltage is normal, but the service information (OSD) is distorted or missing, there is a wide band on the raster, various green symbols are visible Distortion of information in the EEPROM.

There is “rubbish” on the TV screen. graphics, symbols, no TV image, black screen Information distortion in EEPROM.

Malfunctions associated with the lack of sound

No sound. open filter FD801;. non-polar electrolytic capacitor C212 (2.2 μF) is not installed.

There is no sound, On the output MUTE voltage is 2.9 V instead of the prescribed 4.5V The type of the zener diode DZ605 is reversed. instead of a zener diode with a stabilization voltage of 3.3V, it is set to 5.0V (chassis S16A. about IC602).

There is no sound from the LF inputs, there is sound when receiving from the antenna input EEPROM flashing and replacement of the UOC microcontroller did not bring any result. Cause. lack of supply voltage 3.3 V at the pin. 88 IC201S due to poor soldering of the L908 choke.

Malfunctions associated with the lack of reception, the presence of interference

Unable to tune to TV channels Due to breakage of resistor R313 there is no 33 V tuning voltage on the tuner.

Some TV channels are not accepted A resistor is incorrectly installed instead of the capacitor C101 (factory defect).

There is interference on the 4th and 9th terrestrial channels, there is no interference on the other channels.

On the screen there is interference in the form of horizontal stripes on all channels, in the LF input mode there is no interference Capacitor C104 is not installed in the AGC circuit.

The horizontal size is increased and not adjustable Due to the fact that the capacitor CR405S is not installed, the diode D408 is broken (the capacitor is connected in parallel to the diode).

The horizontal size is not correct. Broken capacitor CR409S.

Increased horizontal size One of the pairs of pins of the PC801S optocoupler is not soldered into the board.

Small horizontal dimension Not installed (defective) capacitor C402S.

The horizontal linearity is broken. Due to incorrect marking of the LR402S radar, the beginning and end of the coil are confused (phasing);

samsung, backlight, does, work

Non-linearity of the raster on the sides, in the central part. everything is normal Broken capacitor C415 (0.082 μF x 400 V).

On the right side of the image, the wavy edge is black. The output transistor SRO is heating Diode D403 breakage.

The edges of the raster are wavy The capacitor CR403S is not installed (defective).

The raster on the left side of the screen is crooked Capacitor C414 not installed (defective).

Inversion of the raster horizontally on the left Reason. breakdown of the Zener diode DZ403.

After a short warm-up, the raster size changes and the protection is triggered. 4 (VCC) IC801S (STRW6750F).

The image shows “double contours of the image” Faulty microcontroller IC201 (TDA12025PQ / N1F80).

The image shows “double image contours” on all channels, in the YX mode there is no repetition input. The reason. the filters SF102, SF101 are faulty.

The image shows “tingling”. Replacing the CRT board did not give any results; when the voltage is increased with the Screen regulator, the defect disappears. Cause. IC201 is faulty (TDA12025PQ / N1F80).

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When adjusting the accelerating voltage in the service mode (menu G2), the image acquires a green tint, the image brightness gradually decreases.

The black-and-white image “twitches” (especially on the 10th channel), a slight moire is observed in the color image. The polarity of the capacitor C146 is reversed.

There is no general synchronization. Faulty microcontroller IC201;. open capacitor C133;. short circuit between the terminals of the capacitor C929 from the mounting side;. short circuit of pin 15 of the SCART-2 connector (pin 20 SCART-1) and the output of the resistor R730;. reversed polarity of capacitor C930.

There is only an on-screen menu on the screen. One of the terminals of the capacitor C414 is not soldered;. The capacitor C413 is not installed;. with an increase in the accelerating voltage, the OX mowing line appears. The CUT-OFF voltage on the 5th PC leg is 2.5 V instead of 6.8 V. Reason. capacitor C420 is not installed in the ABL circuit; open resistor R423.

On the right side of the test image, there is a slight disruption of the line synchronization (noise, as with poor filtering) Resistor R818 (33 kOhm) not installed (faulty).

The general synchronization is broken, the mowing line OH is visible on the raster Not soldered (faulty) capacitor C145 (0.15 μF x 400 V).

In the image of the white field in the PAL and SECAM color systems, vertical black stripes 1 cm wide are visible The IC201S microcontroller is faulty.

On any of the test images, noise is observed that resembles high voltage “piercing”, which visually looks like chaotic white dots. streaks, stripes on the image. After a few seconds, the raster begins to “breathe”, after which the output transistor CP (HOT) breaks through. The core (core) of TDKS is destroyed (crack, split).

Twitching the image vertically. Loss of color in the PAL color system, “toffee” in SECAM Faulty IC201S microcontroller.

No image, reverse mowing line is visible on the raster Power supply voltage is normal, there is no distortion of information in the EEPROM. Cause. faulty microcontroller IC201S.

No color in the SECAM color system. Supply voltages are normal. Cause. faulty microcontroller IC201S.

Color distortion or the screen “floods” with blue in the SECAM color system Faulty IC201S microcontroller.

Poor white balance in SECAM Adjusting in the service menu does not solve the problem. The reason is the failure of the EEPROM, it is necessary to reprogram the microcircuit with data from a known working firmware, or install a “clean” memory microcircuit with subsequent correction of the contents (options) in the service menu.

No color in the PAL color system. Defective (not installed) capacitor C930;. Defective microcontroller IC201S.

Dark image. The polarity of the capacitor C202 in the ABL circuit is reversed;. the value of the resistor R418 has increased from 3.9 Ohm to 14 Ohm.

The TV turns off and on on the next channel, after which this process is repeated Trying to measure any voltage leads to nothing. Cause. lack of contact of the kinescope aquadag with the “ground”.

samsung, backlight, does, work

The image is constantly changing on the screen: dot, vertical stripe, full raster When measuring the frequency of H-DRIVE pulses, it is more than 15 kHz. Cause. “earthen” terminal of TDKS is not soldered.

When switching channels on some of them, the image darkens Due to the destruction of the LV102 inductor, 5 V voltage is not supplied to the pin. 63 IC201S.

The raster periodically disappears, the sound remains, with warming up the tendency to disappear increases Replacing the TDA6109JF video amplifier on the kinescope board, the capacitor in the Screen filtering circuit did not solve the problem. A feature has been discovered. if you set the accelerating voltage in the service mode, the TV works for about two hours and again you need to adjust this voltage. Cause. faulty TDKS (FUH-29A001F).

TV is working, there is a reaction to the remote control, there is no control from the local keyboard. All supply voltages are normal, bursts of pulses come to the corresponding input of the processor port. Cause. the IC201S microcontroller is faulty.

When the TV is turned on, the R423 resistor in the ABL circuit burns out.

LED LD901 overheats and burns out Track break from IC201S to R902.

Only the upper half of the raster is visible, it shows the OX mowing line, unstable synchronization, the OSD image is distorted. Supply voltages are normal. Defective microcontroller IC201S.

A “sluggish” image with OX lines appears and disappears. The Q502 transistor is faulty (the “spot” quenching circuit).

When you turn on or connect the antenna, the TV goes into AV mode, then switches to the previously turned on channel The resistor R941 is not installed.

Without an antenna, a black vertical stripe 2 cm wide is observed on the left of the screen, when the antenna is connected, the image on the raster shifts to the right.

Focusing chaotically Faulty TDKS T444S.

When turned on, the screen does not light up Breakage of the LR400S choke, burning of the resistor R426 (1kOhm / 2W).

When working with the LF input from the VCR, the synchronization is lost, and when working with DVD, the image is normal (only for S16A chassis) It is necessary in the VIDEO ADJUST 4 service menu to change the value of the FOA / FOB parameter from 1 to 0.

The image “blinks” (the screen darkens, as if switching channels), at the same time, an OSD image with spontaneously changing image settings (brightness, contrast, saturation) is visible on the screen, but no visual changes occur in the image Reason. breakage of the resistor R911 (13kOhm ).

The control buttons on the local TV keyboard do not work Installing an EEPROM with a known working firmware did not solve the problem. The cause of the malfunction is the IC201S microcontroller.

The image on the left shows a clear black stripe 2-3 cm wide, appearing after 5 seconds. After switching on When TV continues to work, the output transistor SR breaks through. The cause of the malfunction is the IC201S microcontroller.

A bulletin has been issued for the S16C / S16D / S63 chassis related to the appearance of acoustic noise in standby mode, which appears after 5 minutes or more. It is necessary to make a revision. to ground the radiator on which the UMZCH microcircuit is installed, remove the L824 jumper (located to the left of the SCART).

About replacing the IC201S microcontroller and UPS controller

The IC201S microcontroller (TDA12025PQ / N1F80. Paper sticker on the T-GRN2PEU-1014 processor) is replaced, for example, with a similar processor with the T-GRN2PEU-1021 sticker (for today, this is the last existing version of the processor firmware).

Ruslan Kornienko (Kharkov), Sergey Yashin (Kaliningrad)

Attention! Copying the article is strictly prohibited! The article was published with the permission of LLC Publishing House “Repair and Service 21”

How and what faults can be repaired by yourself?

You can eliminate software failures and external violations on your own. That is, breakdowns, the repair of which does not require disassembly of television equipment. It is not surprising, because an ordinary user does not have professional equipment and proper experience at his disposal.

Now we will consider the most common breakdowns that can be repaired by hand.

No sound

Restoring TV involves testing the performance of the power supply, as well as the entire chain: from the adapter to the microcircuit responsible for playing audio tracks. It is possible that the power supply is working, but the microcircuit is damaged.

Basic malfunctions of Samsung TVs

If we talk about the models of the first generation of LCD TVs, then first of all it should be said about the problem of electrolytic capacitors in the filters of the power system modules. However, the manufacturer took into account the weak link in this system, so the owners of LED models rarely encounter this type of breakdown. It is possible that this is due to the lower power consumption of diode backlight converters.

Continuing to use your TV with broken power filters is likely to cause software malfunctions. First, the search settings on the TV will be erased, you will have to search for channels again. Secondly, various image distortions will gradually begin to appear. Thirdly, the backlight of the screen will not work correctly. A complex software glitch will cause the device not to turn on at all.

Therefore, there is no need to delay. Repair the LCD TV power supply and then replace the contents of the EEPROM.

We figured out electrolytic capacitors, but this is far from the only typical malfunction of Samsung TVs, which manifests itself in a breakdown of the power supply:

  • Ring cracks in the soldering of the transistor.
  • Breakdown of the sealant with subsequent closure and breakage of the resistor.

Thus, the power supply system is perhaps the most vulnerable node of Samsung television equipment.

To eliminate defects in the image, they are often presented in the form of stripes tilted to the side, it is necessary to replace the capacitor on the motherboard. There is absolutely no need to replace this module in a TV set-top box.

A huge number of LED models, especially the 5 series, are equipped with matrixes with poor quality LED backlighting. Sometimes there are devices in which the voltage across the diodes is incorrectly calculated. This defect will make itself felt even during the first year of operation of the equipment. Over time, the image fades, and then disappears altogether.

Separately, it is worth talking about such problems as frame scanning and line scanning. This is a hardware failure that manifests itself in the form of image distortion. Problems with horizontal scanning appear due to damage to the winding. It is necessary to restore it and change the stabilizers to improve the voltage level. With the frame scan, everything is a little more complicated, sometimes you have to change the roll, and in some cases the transistors.

Of course, mechanical damage to the screen should be included in the list of typical malfunctions. Such a breakdown occurs due to non-observance of the operating rules, it is solved by replacing the matrix and backlight.

When you need a master?

Only a qualified technician can fix hardware breakdowns. Therefore, if the Samsung Smart TV power supply burns out or dots appear on the screen, be sure to contact the service center for help.

Problem search algorithm

Regardless of where the repair is carried out: at home or in a professional workshop, you first need to diagnose the malfunction, determine the cause of the breakdown. A convenient concept has been developed especially for you to quickly identify the source of the problem. The algorithm allows the user to diagnose and eliminate the malfunction himself.

We bring to your attention a table that shows common symptoms and their interpretation, that is, because of what they appear. Based on this instruction, even a beginner will be able to quickly determine why the ICE screen does not work or establish any other malfunction.

Damaged power cord, burned out power adapter, broken power button

The screen is not backlit, the picture is there, but it is very dim

The lamp or LEDs do not work, malfunctions in the backlight power system are possible

No sound or very wheezing

The sound card amplifier, strapping (microcircuit and accessories located next to it) is out of order

The TV screen lights up but there is no picture

The tuner and its circuits are broken, problems with the GPU are not excluded

Note that in no case should you run ahead, start diagnostics with a visual inspection of the equipment used. In the event that you find darkening on microcircuits or carbon deposits, rupture of components, do not rush to replace them. The elements of the hardware component that have burned out may be a sign of a short circuit, respectively, it is possible that the source of the problem is located in a completely different place. Before starting diagnostics, be sure to disconnect the power to the television equipment.

TV broadcast setting

If you have a “digital” connected, but at the same time all channels have disappeared, then do not rush to call the service center. First you need to try to restore them yourself. Perform manual or automatic tuning. Also try to adjust the antenna, point it towards the tower. Switch channels and change the position of the antenna in parallel to fix the optimal vector.

Is it possible to replace the backlight yourself?

The backlight is a fairly simple electronic component. It consists of several tens or hundreds of white LEDs. Usually, these LEDs are combined into strips located horizontally or vertically with the same distance between them. For example, the photo below shows the backlight module for Samsung TVs of the 42LA6230 range:

Each of the 5 LED strips has 10 LEDs in its design, i.e. there are 50 in total. The strips can be removed from the backlight module and then easily replaced with new ones.

A special case of backlight failure. burnout of one or more LEDs. is shown in the image below:

From here you can see that the LED strips are located behind the screen module of the TV. Those. they can be repaired or replaced at any time. But it is not recommended to do this without experience in the repair of delicate electrical equipment.

The reasons for the inoperability of the backlight

Backlight failure can be due to one of two reasons:

  • Problems with the backlight itself.
  • Backlight control module (driver) malfunctions.

Sometimes the backlight is inoperative due to both reasons at the same time, but this is quite rare.

The very same malfunction of one or another electronic component of the TV screen most often becomes the result of voltage surges in the mains. If the power supply unit of the TV receiver receives a voltage that does not correspond to the values ​​required for operation, it may malfunction. Bursts of output current, voltage, frequency, etc. may cause the backlight itself or the control module to burn out. Often the only way out of the situation is to replace burnt out components.

The principle of operation of LED / OLED-matrices

It is important to know the principle of operation of the matrices of modern TVs for one reason. the failure of the backlight is not such a serious problem. The TV receiver screen itself is made of millions of colored LEDs of low brightness. To be able to see the picture on the TV screen, the matrix is ​​equipped with a bright white LED backlight. It is its light, which is subsequently colored by LED / OLED LEDs of the matrix, that we see on the TV. The design of the LED screen module of modern television sets looks like this:

The diagram shows that the backlight is an auxiliary component of the TV screen module. The failure of this device does not affect the operation of the screen itself. This is easy to verify. Turn on the TV (it is desirable that there is no light in the room) and direct the light from the flashlight to the screen. In the place where the light from the flashlight falls, the picture currently displayed on the screen will be noticeable. For example:

The photo shows that in the place where the rays from the flashlight fall, the image from the TV screen is slightly visible. If in your case the same picture is observed, then the matrix of the TV receiver is working properly. this is good news, because its replacement will cost about 70% of the cost of the TV itself. If only the backlight needs to be repaired, then this procedure is not so expensive.

Why Samsung TV Backlight Doesn’t Work. Causes and Troubleshooting

Most modern TVs from Samsung or another company are LED or OLED. This means the presence of a backlight in the design of the matrix (screen) of the TV receiver. If this electronic component fails, it will be very difficult to see the picture on the TV screen. What can be done if the backlight fails? Let’s figure it out.

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Burnout driver backlight

The backlight driver (controller) is just a small microcircuit placed on a separate or included in the design of the main control board of the TV. For example, this photo shows the MAP3202 driver, which is responsible for controlling the backlight on Samsung TVs of the 32LN540V series:

The microcircuit is large enough so that it can be re-soldered, if necessary, using the most ordinary soldering iron. In addition, this particular driver has a low cost. about 1-2. Those. if you have tools and skills in soldering, you can repair the LED backlight control board yourself.

When to contact the service center?

The failure of the TV backlight can be associated with hardware malfunctions of other electronic components. power supply, motherboard, etc. To establish the cause of the malfunction, a thorough diagnosis of all electronic components of the TV receiver is required, which cannot be done at home without the presence of special tools and diagnostic devices. In such cases, the most correct solution would be to contact the workshop.

Samsung UE32F5020AK LCD Backlight Repair

One of the most common defects in LED TVs is the missing screen backlight. Visually, this defect looks very simple: “There is sound. there is no picture,” but this is not entirely true. If you look closely at the TV screen and additionally shine a flashlight on it, you can see what is happening on the screen after all, what kind of action. If this is the case, then the defect is most likely caused by a faulty diode illumination of the image. As a rule, if one or two diodes burn out, the “brains” of the TV allow the backlight to work further, but a larger number is already critical and the backlight goes out completely. Some TVs still show an image at startup, and then the screen goes out, and some don’t show anything right away. This is due to different software settings as well as the severity of the fault. Today we will look at the repair of the backlight using the example of the Samsung UE32F5020AK TV.

Samsung TV Back Cover Samsung TV Contents

Samsung LED TV backlight troubleshooting and repair

Any repair begins with disassembling the device and each device has its own nuances. In our case, you need to pay attention to the small cover, which must be removed before removing the main cover, because under it there is a connector into which the button control on the TV case is inserted and it must be turned off. After that, unscrew and remove the main back cover. The back cover is removed and we can see all the insides of the TV. And this is just the Motherboard (Main board), Power Supply Unit (Power Supply Unit), speakers, ribbon cable to the T-Con board and the T-Con itself (Time Controller). Disconnecting the cables from the T-Con board to the matrix strips.

Next, we proceed to the analysis of the “Matrix”. It is recommended to approach the removal of the main frame very carefully, since it is very well fixed with latches. and many craftsmen prefer to use “shovels” for prying the frame and bending it, but there is one nuance in this issue and it must be approached very responsibly. The name for this nuance is “lateral matrix drivers”, in the common people “Petals”. If you pry it with a spatula or any other similar tool, you can hook the petal, or rather the crystal that is on it. As you can see in the photo, it is located just on the inside of the driver. Unfortunately, if the integrity of the crystal is violated, then a defect in the form of lines will appear on the image and it will be impossible to restore the integrity. Either you need to change the glass, or the matrix assembly or the petal. But, unfortunately, it is practically impossible to carry out the last procedure in the stationary conditions of the service center. And the price will not be much cheaper than replacing the matrix assembly (unless, of course, we are talking about inexpensive TVs). We removed the frame, did not hook anything, and we can continue further. We make sure that nothing bothers us, there are no unnecessary objects (tools, devices) nearby, we take out the matrix strips from the grooves, put on anti-static gloves and very carefully remove the glass. You can’t put it anywhere, since glass is very fragile and you need to exclude the interaction of glass with anything as much as possible. We lean him against the wall behind the workplace. Then we remove the frame on which the glass lay. It is secured in a circle with latches. Snap them off shouldn’t be a problem. Removing polarizing sheets. And now we almost got to the diode lines. The last sheet remains, but it is fixed with clamps, which play two roles. The first role is to hold the main reflector and the second is to prevent the top polarizing sheets from sinking. Removing them on our TV is also not difficult. They must be turned and removed. This is done by hand, however, if the hand does not work, you can use the tool. The main thing is not to overdo it and not break them. So. Everything is ready for renovation. Now you need to identify the faulty diodes and replace them.

We use a special device to identify faulty diodes. A defective diode can be either in a short circuit or simply burned out. These are two fundamentally different defects, since if the diode is burned out and is, for example, at the very beginning of the line, then when the ruler is called in its entirety, all diodes, except for our culprit, will light up

Defective Samsung TV LED backlight

And if the diode is closed, then the ruler will not light, since it will not receive feedback to ignite the remaining diodes. In this case, you will either have to ring each diode separately, or look for working segments. In this photo, the second diode on the left is in a short circuit, and the fourth just burned out. After searching for faulty diodes, we remove the rulers on which there are such and proceed to replacement. Remove the diffusing lens from the faulty diode and check it again using the device.

We made sure that it really does not burn and we are starting to replace it. You can unsolder and solder using a soldering iron or a hair dryer. But in our opinion, soldering with a hair dryer is easier and better. For this job we use a soldering station.

Soldering station LUKEY 852D Diode pad of matrix Samsung

We hang the bar in such a way that it is possible to warm up the platform on which the diode is fixed with a hairdryer from below and unsolder it. Next, we apply flux and apply a working diode to the site and also solder it back using a hair dryer. It is important not to confuse the polarity of the diode, and it is also recommended to use the same diodes that are on a particular bar, of course, not only in voltage, but also in shape. The site in our case looks like this. Very often TVs with a similar defect come in for repair, but after another service, where, in the absence of suitable diodes, they solder anyhow, anyhow. Of course, such work does not bring a lasting result and you have to redo it, and the Client must pay extra money. So. The diode is replaced, we check again with the device.

The next step is to return the diffuser lens to its place. This is a very serious step, because it determines how the diode in the already assembled LCD module will shine.

If the lens is not attached exactly in the center, but is shifted slightly to the side, then the scattering will not be even, and, as a result, on the scattering sheets, instead of even light, so-called halos around the lens will be visible. And if the lens is moved quite a bit, then most likely they will not be visible in the image, or will be, but only against a bright white background, but if they are displaced strongly, then they will be noticeable in almost any picture and any color.

Lenses replaced. We install the bars in their place, turn on the power to the TV and check

Samsung glass after replacing the diode backlight

All diodes are on, the backlight is restored. We are starting to assemble our device back. During the collection process, I recommend turning it on two more times. The first time we put all the polarizing layers in place to make sure there are no ghosting. And also after we put (but do not fix) the glass. We connected, checked, everything works. Now comes the hardest part! The last frame that covers the glass is the bezel of our TV. The fact is that the more modern the TV is, the thinner the frames are used. There are different variations of frames. Some twist, others snap, but the main point is the same. the glass is placed on the frame in the grooves. the grooves are designed so that there are practically no gaps between them and the glass. Thus, if you put the glass a little crooked and miss, and then snap the front frame, the result will be sad. If the matrix glass has even a small inconspicuous chip, then, alas, the image will be damaged. Any small damage to the matrix leads to irreversible consequences and it will no longer be possible to watch such TV. So. The TV is assembled, the image has appeared. All right. But this is not the end of our renovation. In order to prevent this defect from repeating itself, in an amicable way, we still need to modify the power supply unit. The fact is that a large current is supplied to the backlight for a bright glow of the diodes when it is required and, accordingly, the life of the diodes, which directly depends on the current, is reduced. We use the practice of decreasing the current for a correspondingly longer diode life. This does not affect the image quality, but this affects the increase in the life of the diodes in the best way.

Backlight resistor on Samsung TV PSU

In this case, we find a backlight resistor on the power supply. Its parameter is 3.4 Ohm and we change it to a larger one, or we sequentially increase its parameter with another resistor. In our case, we took another 1.2 Ohm resistor and sequentially soldered to this.

Refinement of the backlight in the Samsung TV power supply

One of the most common defects in LED TVs is the missing screen backlight. Visually, this defect looks very simple: “There is sound. there is no picture,” but this is not entirely true. If you look closely at the TV screen and additionally shine a flashlight on it, you can see what is happening on the screen after all, what kind of action. If this is the case, then the defect is most likely caused by a faulty diode illumination of the image. As a rule, if one or two diodes burn out, the “brains” of the TV allow the backlight to work further, but a larger number is already critical and the backlight goes out completely. Some TVs still show an image at startup, and then the screen goes out, and some don’t show anything right away. This is due to different software settings as well as the severity of the fault. Today we will look at the repair of the backlight using the example of the Samsung UE32F5020AK TV.

Samsung TV Back Cover Samsung TV Contents

Any repair begins with disassembling the device and each device has its own nuances. In our case, you need to pay attention to the small cover, which must be removed before removing the main cover, because under it there is a connector into which the button control on the TV case is inserted and it must be turned off. After that, unscrew and remove the main back cover. The back cover is removed and we can see all the insides of the TV. And this is just the Motherboard (Main board), Power Supply Unit (Power Supply Unit), speakers, a ribbon cable to the T-Con board and the T-Con itself (Time Controller). Disconnecting the cables from the T-Con board to the matrix strips.

Next, we proceed to the analysis of the “Matrix”. It is recommended to approach the removal of the main frame very carefully, since it is very well fixed with latches. and many craftsmen prefer to use “shovels” for prying the frame and bending it, but there is one nuance in this issue and it must be approached very responsibly. The name for this nuance is “lateral matrix drivers”, in the common people “Petals”. If you pry it with a spatula or any other similar tool, you can hook the petal, or rather the crystal that is on it. As you can see in the photo, it is located just on the inside of the driver. Unfortunately, if the integrity of the crystal is violated, then a defect in the form of lines will appear on the image and it will be impossible to restore the integrity. Either you need to change the glass, or the matrix assembly or the petal. But, unfortunately, it is practically impossible to carry out the last procedure in the stationary conditions of the service center. And the price will not be much cheaper than replacing the matrix assembly (unless, of course, we are talking about inexpensive TVs). We removed the frame, did not hook anything, and we can continue further. We make sure that nothing bothers us, there are no unnecessary objects (tools, devices) nearby, we take out the matrix strips from the grooves, put on anti-static gloves and very carefully remove the glass. You can’t put it anywhere, since glass is very fragile and you need to exclude the interaction of glass with anything as much as possible. We lean him against the wall behind the workplace. Then we remove the frame on which the glass lay. It is secured in a circle with latches. Snap them off shouldn’t be a problem. Removing polarizing sheets. And now we almost got to the diode lines. The last sheet remains, but it is fixed with clamps, which play two roles. The first role is to hold the main reflector and the second is to prevent the top polarizing sheets from sinking. Removing them on our TV is also not difficult. They must be turned and removed. This is done by hand, however, if the hand does not work, you can use the tool. The main thing is not to overdo it and not break them. So. Everything is ready for renovation. Now you need to identify the faulty diodes and replace them.

Samsung TV LED backlight failure

We use a special device to identify faulty diodes. A defective diode can be either in a short circuit or simply burned out. These are two fundamentally different defects, since if the diode is burned out and is, for example, at the very beginning of the line, then when the ruler is called in its entirety, all diodes, except for our culprit, will light up

Defective Samsung TV LED backlight

And if the diode is closed, then the ruler will not light, since it will not receive feedback to ignite the remaining diodes. In this case, you will either have to ring each diode separately, or look for working segments. In this photo, the second diode on the left is in a short circuit, and the fourth just burned out. After searching for faulty diodes, we remove the rulers on which there are such and proceed to replacement. Remove the diffusing lens from the faulty diode and check it again using the device.

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We made sure that it really does not burn and we are starting to replace it. You can unsolder and solder using a soldering iron or a hair dryer. But in our opinion, soldering with a hair dryer is easier and better. For this job we use a soldering station.

Soldering station LUKEY 852D Diode pad of matrix Samsung

We hang the bar in such a way that it is possible to warm up the platform on which the diode is fixed with a hairdryer from below and unsolder it. Next, we apply flux and apply a working diode to the site and also solder it back using a hair dryer. It is important not to confuse the polarity of the diode, and it is also recommended to use the same diodes that are on a particular bar, of course, not only in voltage, but also in shape. The site in our case looks like this. Very often TVs with a similar defect come in for repair, but after another service, where, in the absence of suitable diodes, they solder anyhow, anyhow. Of course, such work does not bring a lasting result and you have to redo it, and the Client must pay extra money. So. The diode is replaced, we check again with the device.

The next step is to return the diffuser lens to its place. This is a very serious step, because it determines how the diode in the already assembled LCD module will shine.

If the lens is not attached exactly in the center, but is shifted slightly to the side, then the scattering will not be even, and, as a result, on the scattering sheets, instead of even light, so-called halos around the lens will be visible. And if the lens is moved quite a bit, then most likely they will not be visible in the image, or will be, but only against a bright white background, but if they are displaced strongly, then they will be noticeable in almost any picture and any color.

Lenses replaced. We install the bars in their place, turn on the power to the TV and check

Samsung glass after replacing the diode backlight

All diodes are on, the backlight is restored. We are starting to assemble our device back. During the collection process, I recommend turning it on two more times. The first time we put all the polarizing layers in place to make sure there are no ghosting. And also after we put (but do not fix) the glass. We connected, checked, everything works. Now comes the hardest part! The last frame that covers the glass is the bezel of our TV. The fact is that the more modern the TV is, the thinner the frames are used. There are different variations of frames. Some twist, others snap, but the main point is the same. the glass is placed on the frame in the grooves. the grooves are designed so that there are practically no gaps between them and the glass. Thus, if you put the glass a little crooked and miss, and then snap the front frame, the result will be sad. If the matrix glass has even a small inconspicuous chip, then, alas, the image will be damaged. Any small damage to the matrix leads to irreversible consequences and it will no longer be possible to watch such TV. So. The TV is assembled, the image has appeared. All right. But this is not the end of our renovation. In order to prevent this defect from repeating itself, in an amicable way, we still need to modify the power supply unit. The fact is that a large current is supplied to the backlight for a bright glow of the diodes when it is required and, accordingly, the life of the diodes, which directly depends on the current, is reduced. We use the practice of decreasing the current for a correspondingly longer diode life. This does not affect the image quality, but this affects the increase in the life of the diodes in the best way.

Backlight resistor on Samsung TV PSU

In this case, we find a backlight resistor on the power supply. Its parameter is 3.4 Ohm and we change it to a larger one, or we sequentially increase its parameter with another resistor. In our case, we took another 1.2 Ohm resistor and sequentially soldered to this.

Refinement of the backlight in the Samsung TV power supply

Samsung TV UE32ES5507

Brand: Samsung, model: UE32ES5507V, model code: UE32ES5507VXRU (Russia). Short from TV: LCD, LED backlight, 32 “, 1920×1080, 1080p Full HD, PIP, DVR, sound: 20W, HDMI connectors: 3, access to the Internet, Smart TV.

The Samsung website has a firmware (software update) for UE32ES5507KXRU, UE32ES5507VXRU, version 2008.0 dated 10/12/2017. details.

Includes MainBoard BN41-01812A BN94-059970Q and LCD-panel LE320BGM-C1 Power Supply Unit (PSU) BN44-00501A PD32A1_CSM Power Supply.

Repair documentation available for download on the page below.

If the screen is broken or cracked

The LED screen of the Samsung UE32ES5507 TV requires careful handling. The glass can crack even when lightly hit by a child’s toy. Excessive pressure on the screen surface over any part of the area is equally dangerous.

If the screen is damaged, you will need to replace the LE320BGM-C1 LED panel. In such cases, the price should be checked at the Samsung Authorized Service Center by the phone numbers indicated in the accompanying documents, or on the manufacturer’s official website. In most cases, such repairs are economically inexpedient.

Recommendations for Samsung UE32ES5507 users

If the TV malfunctions, it is advisable to inquire about the manufacturer’s (seller’s) warranty obligations in the accompanying documents (warranty card).

If the Samsung UE32ES5507 does not turn on or periodically turns off, you should check the sockets and extension cords where the TV is connected to the network.

If the Samsung UE32ES5507 does not respond to the remote control, but the buttons on the TV control panel work, there is a certain probability of the remote control malfunction (the remote control does not work). It is advisable to check or replace the batteries in it.

If, when watching on-air programs, a notification of no signal appears (no signal), you should check the antenna or cable equipment and the program settings. If necessary, you can make sure that the TV is working from other external devices.

If there is no sound when watching analogue TV programs, you should check the sound system in the settings. For Russia D / K (6.5 MHz), for Europe B / G (5.5 MHz). In modern televisions, a region is usually chosen to set color and sound standards. for Russia “East Europe”.

If Samsung UE32ES5507 freezes during operation, does not respond to either the remote control or the control panel buttons, sometimes restarting helps. To do this, you must completely disconnect the TV from the network by pulling out the plug from the outlet, and after 10-15 seconds turn it on again.

Main technical characteristics:

Repair assistance. PDF document available.

Service Manual 169 pages in 2012 to UE26EH4500 model, UE26EH4510, UE32EH5300, UE32EH5307, UE40EH5300, UE40EH5307, UE46EH5300, UE46EH5307, UE50EH5300, UE32ES5500, UE32ES5507, UE32ES5530, UE32ES5537, UE32ES5550, UE32ES5557, UE37ES5500, UE40ES5500, UE40ES5507, UE40ES5530, UE40ES5537, UE40ES5550. UE40ES5557, UE46ES5500, UE46ES5507, UE46ES5530, UE46ES5537, UE46ES5550, UE46ES5557, UE50ES5500, UE50ES5507, UE50ES5530, UE50ES5537, UE50ES5557, UE32ES5700, UE37ES5700, UE40ES5700, UE46ES5700, UE50ES5700, UE32ES5800, UE40ES5800, UE46ES5800, UE32EH5450W, UE40EH5450W, UE46EH5450W, UE22ES5400W, UE22ES5410W.

Model: UE32ES5507

Additional picture features: True Cinema (24 frames).

Additional Sound Features: Surround Sound.

It is possible to mount the TV to the wall.

Indicator shines red

The situation when the TV cannot be turned on from the remote control or the buttons on the device itself, and the indicator is on, is common. Usually, in such cases, they say: “The TV does not come out of standby mode.” There may be several reasons for this, but you need to start with the most obvious ones. Replace the batteries in the remote control, remember from which button the TV was turned on earlier and, if this does not help, call the master on the TV or, with the proper skill, start an independent TV repair.

The glow of the indicator is more or less likely to indicate the health of the power supply. However, the diagnosis of this malfunction, like most others, should be started with an analysis of the operation of this board. Checking voltages in standby mode, their stability when trying to turn on in the operating mode, measuring the level of filtration, visual inspection of parts helps to assess the health and functionality of the power supply. Electrolytic capacitors, the upper part of which has a characteristic swelling, must be replaced.

In the section “Malfunctions of TVs”, the real history of repairs of TVs with a similar manifestation of a defect is considered on the example of TVs Philips 42PFL7433S / 60, Samsung LE40R82B, Philips 20PF5121 / 58 and other models. The behavior of television sets was somewhat different, but the reason was the same. There was a change in the properties of electronic components, mainly capacitors, in which the power supply could not provide a confident start, affecting the operation of the entire system so that the indication was present, and the TV did not turn on. If in one case the malfunction was visible to the naked eye, then in the other, its localization required a long process of diagnostic measures and measurements.

The elimination of an obvious defect in the power supply does not always lead to normal operation of the TV as a whole. In some cases, an unstable power supply leads to the loss of information in the Eeprom and SpiFlash memory chips. At the same time, it is possible to turn on the TV and switch it to operating mode only by updating the software (firmware) on the programmer. The workshop is equipped with these devices in sufficient quantity for different types and cases of microcircuits. When repairing with your own hands, difficulties may arise with firmware without equipment and a firmware database for television models, and contacting a service organization in such a situation is morally and economically justified.

Sometimes such troubles occur when there is a malfunction in the power circuits on the TV’s motherboard. Usually in this block there are several secondary sources, made according to the scheme of DC-DC converters or voltage stabilizers. An indispensable condition for the correct operation of the processor and devices associated with it is a stable supply voltage in the voltage range at which their normal functionality is ensured. In cases where these conditions are not met, the consequences can be unpredictable, and the command to turn on the device can be ignored until the necessary power supply parameters are provided.

The indicator turns green, but nothing happens

The situation is ambiguous and can have many reasons for this behavior. In order to make sure that the main board is working, the supply voltages are measured and the commands to turn on the power, backlight, etc. are examined. Perhaps, when you switch the TV to a channel with a tuned program, a sound will appear, and this already suggests that the cause of the malfunction most likely lies in the inverter or power supply unit with LED backlighting or in radiation sources.

If the LED (light bulb) indicates the operating state, but the power-on commands are not received from the motherboard, the system does not respond to the buttons and the remote control, the software of the memory devices on the main board may fail. There are situations when the processor issues a command to turn on the power supply, but does not start the inverter, or issues a Dimm command that determines the brightness of the backlight, in the absence of an On / Off command. In this case, updating the software, firmware helps to return the normal sequence to the logical processes occurring on the motherboard.

In some cases, the appearance that nothing happens when turned on can be created by the motherboard, blocking the supply of signals to the matrix controller or transmitting such information in which the screen remains dark. The T-con itself may be faulty, as well as the LCD matrix itself. Each option is considered and diagnosed separately. At the same time, the backlight turns on, but has a weakly pronounced character due to the underestimated image brightness.

The indicator (light bulb) constantly flashes chaotically

This state of the device only indicates a malfunction and does not contain significant information about possible problems. It is necessary to diagnose the entire device, starting with checking the power supply and secondary converters on the system board. Further, the buses for the exchange of information between the processor and memory microcircuits, the sending of commands by the processor to turn on and the processing of these commands by the peripheral components of the television chassis are investigated.

The indicator changes color to green and back to red

This behavior most often indicates that the processor generates a command to turn on the device and sends it to all executors. If any of the TV units does not execute the command, for example, the power supply does not turn on in operating mode or the inverter is not able to start the backlight, then the processor, without receiving confirmation that everything is in order, cancels the power on and puts the device back into standby mode. In Sharp LCD TVs, after five unsuccessful attempts to turn on the backlight, the processor blocks the startup altogether, until the errors are cleared through the service menu or until the contents of the Eeprom memory are replaced. This behavior will continue until the cause is eliminated: defective lamps replaced, inverter, power supply, or other faulty component of the TV chassis repaired.

The indicator flashes in a specific sequence

In television receivers of some manufacturers: Sony, Philips, Panasonic. self-diagnosis of the TV is provided at the moment it is turned on. As a result of polling via SDA and SCL buses, the central processor receives information about the operability of other functional devices: tuner, sound processor, memory chips, the digital bus itself, etc. If a faulty node is detected, the turn-on command is blocked and the receiver goes into standby mode with error indication. The light indicators start blinking in a certain sequence, indicating a particular error in the device.

This self-diagnosis method allows you to quickly identify the faulty component. The service instructions for a specific model contain the so-called error codes, in which each combination of flashing indicators corresponds to possible failures of various components of the TV receiver. This greatly facilitates the life of the telemaster when diagnosing, directing him along the right path. For example, a paused 13 LED blinks on a Sony TV on a FIX2 chassis indicates a problem with the backlight. An inverter or lamps can be faulty, so we will diagnose them. As an example, I will give a table with error codes for Philips TVs on the Q552.1E LA chassis. The first level of errors (Layer 1) we see immediately when a defect occurs, the second level (Layer 2) can be observed if the receiver is switched to service mode.

Summing up, we can say that the behavior of the indicator light in the TV when a malfunction occurs can provide a lot of useful information for the successful diagnosis and localization of a defect in a particular unit, contributing to the successful repair of the TV as a whole.

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