In detail: do-it-yourself LCD TV repair does not immediately turn on from standby mode from a real master for the site my.housecope.com.
As you know, when you turn on the TV to the power grid, it first goes into standby mode, as evidenced, in particular, by the glow of the indicator. At the same time, most of the TV nodes (tuner, radio channel, kinescope, etc.) remain de-energized. In the future, to view television broadcasts, the TV is switched to operating mode. During the operation of TVs, malfunctions associated precisely with the standby mode are often encountered.
Basically, there are 3 typical malfunctions:
the TV does not turn on in standby mode;
the TV does not switch from standby to working;
the TV does not switch from operating mode to standby.
The TV does not turn on in standby mode, the standby indicator does not light
Such malfunction symptoms indicate a malfunction of the TV's power supply, as well as its loads.
In addition, it is advisable to check the presence of the control signal STDBY (standby mode) on the actuator, as well as the operability of the actuator itself.
The cause of this defect may be a malfunction of the control processor IC1101, transistor Q850 and relay RL801.
First of all, they check (with an oscilloscope or a tester) whether there is a pin. 24 IC1101 control signal. If not, then the IC1101 processor (MN152811 TZX) is defective and needs to be replaced. If the control signal comes to the Q850 transistor, and the latter does not open, then the transistor is out of order. And finally, if the Q850 transistor opens and the relay does not work, then the RL801 relay (TSE10817) must be replaced.
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In operating mode, the RL801 relay must be energized, the relay armature connects contact C to contact A and the power supply is fully turned on.
The reason for this defect may be the same control processor IC1101, transistor Q850 and relay RL801.
If the control processor does not issue a signal to enter standby mode (pin 24 of IC1101), then the control processor is replaced.
If there is control from the processor, but the Q850 transistor does not close (perhaps the emitter-collector transistor junction is broken), then the Q850 transistor must be replaced.
And finally, if the Q850 transistor closes, and the relay armature does not switch, then the following RL801 relay malfunctions are possible:
The contact group of the relay is "stuck" in the AC position. In this case, replace the RL801 relay.
The mains fuse blows when the TV is turned on.
A malfunction most often occurs due to short circuits in the primary circuits of the power source, which are usually caused by surges in the mains voltage, as well as short circuits of conductors as a result of external pollution and household insects entering the TV.
Possible faulty elements in it: mains noise suppression filter C633 LF600 C634 LF601 C635, rectifier D600, capacitors C601 - C603, key transistor of the IC600 microcircuit.
To find a faulty element, after disconnecting the TV from the mains, disconnect the connectors of the demagnetization loop and speaker CN601 and CN1200. The board is placed in the repair position. Measure the resistance between the terminals of the capacitor C603, having previously discharged it through a resistor with a resistance of 200.500 Ohm with a power of 2 W. The resistance of a good circuit must be at least 10 kOhm. With a lower resistance or a short circuit, to speed up the search for the cause of the malfunction, one of the terminals of the resistor R647 is soldered.Thus, the primary circuit of the power supply is divided into two parts: a filter with a rectifier and a microcircuit. The resistance between the terminals of the capacitor C603 is measured again. If the short circuit still occurs, check the serviceability of the rectifier and filter elements. The most common failures are rectifier diodes D600 and capacitors C601 - C603.
In the event of a malfunction of the capacitors C601, C602, it is temporarily permissible for the TV to work without them.
The malfunction of the C603 capacitor can be easily identified visually by the swelling on the top of its case, the rupture of the safety notch or traces of liquid on the board. Defective diodes are replaced with serviceable similar types with parameters: maximum current not less than 2 A, reverse voltage not less than 400 V.
With a low resistance between the terminals of the capacitor C603, they check the operability of the IC600 microcircuit, in which the key transistor with terminals 1-3 (collector, emitter, base, respectively) most often fails.
When repairing a switching power supply, it must be remembered that a number of its circuits have a galvanic connection with the mains. Therefore, it must be connected via an isolation transformer.
TV does not turn on, mains fuse intact
Troubleshooting begins with measuring the DC voltage across the filter capacitor C603, which should be within 270. 310 V. If it is absent, then sequentially check for the presence of voltages on the line filter and the input of the rectifier bridge. One of the reasons for the lack of voltage may be the failure of one (or both) breaking resistors R631, R642, and this, in turn, may be due to a malfunction of the following elements: C603, D600, IC600, C602, C601.
The defective element is found using an ohmmeter.
If the required voltage is available on the C603 capacitor (270. 310 V), then check its presence on the C608 capacitor. If it is absent, then check the serviceability of the resistor R647 and winding 6 - 8 of the T601 transformer.
Then they check the health of the key transistor of the microcircuit and the presence of a supply voltage (7.7 V) at the pin. 9 microcircuits. If the supply voltage is significantly underestimated or completely absent, check the serviceability of the R600 D601 circuit. The following elements most often fail: R605, Q601, D603, C607 (check by replacement), R606.
Short circuits at the outputs of the secondary rectifiers of the power supply can also lead to the defect in question.
The TV does not switch from standby to working. When you try to switch, the standby indicator goes out for 1.2 s and lights up again
If a visual inspection of the installation does not reveal burnt resistors, swollen capacitor cases, traces of soot near the line transformer, then you need to pay attention to the nature of the sound that accompanies turning on the TV.
If at the same time a characteristic sound from a high voltage surge is heard, this means that trigger pulses are applied to the horizontal output stage. Then it can be assumed that the microcontroller, memory and video processor are in good order, and the faults are contained in the circuits of the TDKS line transformer or frame scan.
It is impossible to make an erroneous conclusion about the serviceability of the TDKS even in the presence of the specified sound, because a breakdown can be in its high-voltage part when an anode voltage appears.
Next, connect the oscilloscope to the protection bus (pin 9 of the CN001 connector of the board A) and turn on the TV. If a voltage of 5 V appears at least for a short time, it means that the microcontroller with a PROT protection signal for some reason blocks the activation of the operating mode. It is necessary to find out from which of the sensors this signal comes. To do this, the sensors are turned off one by one and each time they try to switch the TV to operating mode. First, the protection sensor against a malfunction in the vertical scan circuits is turned off, for which one of the terminals of the D505 zener diode is soldered (board D).If at the same time a bright horizontal strip appears on the screen, and the PROT voltage drops to zero, then the fault is contained in the vertical scan circuits. It is necessary to ensure that the horizontal stripe is not on the screen for a long time in order to avoid burn-through of the kinescope phosphor.
Then they check for the presence of supply voltages at the pins of the IC500 microcircuit: 15 V at the pin. 2 and -15 V on pin. 4, serviceability of elements D504, R508, the presence of personnel sync pulses on the pin. 5 microcircuits.
After that, it is concluded that it is necessary to replace the IC500 microcircuit.
You can check the serviceability of the vertical scan circuits in another way. Connect the oscilloscope to the frame deflection coils and turn on the TV. If frame pulses with an amplitude of 60 V appear for at least a fraction of a second, it means that the vertical scanning circuits are in good order and the malfunction must be looked for in another section of the circuit. If there are no pulses, then check for the presence of CSI on the pin. 1 IC500, as well as the appearance of the supply voltage of the microcircuit at the moment the TV is turned on.
If, after disconnecting the sensor, the TV turns on, then the fault is in the protection circuits. Check the health of the following elements: Q501 - Q503, D504, D505, D507.
If the voltage on the PROT bus remains at 5 V, turn off the horizontal output stage. To do this, with the vertical scan sensor turned off, a jumper is installed between the base and the emitter of the Q802 transistor, which leads to its closure and disruption of horizontal scan oscillations. If at the same time the voltage on the PROT bus drops to zero, then the TDKS or the kinescope are faulty. The panel is removed from the base of the picture tube and the high-voltage wire is disconnected. Remove the previously installed jumper and turn on the TV. If at the same time the voltage on the PROT bus drops to zero again and a high voltage appears, then the kinescope is faulty, otherwise the TDKS is faulty.
If the voltage of 5 V on the PROT bus remains, then this indicates either the presence of a large current consumption in the circuit of the 135 V voltage source, or a malfunction of the protection transistors Q607, Q602 - Q605 of the power supplies. A faulty transistor is detected with an ohmmeter.
If the voltage on the PROT bus is zero, and the TV does not switch to operating mode, then check the presence of voltage on the pin, 3 IC602 microcircuits, power supply to the IC001 microcontroller, and a RESET signal to its pin. thirty.
The initial reset node (RESET), made on the basis of the IC004 chip of the board A, is operational if, when you turn on the TV on the pin. 4 microcontrollers IC001 hold a potential of 0 V for a short time, and then gradually increases to 5 V. Using an oscilloscope, they measure the time during which the voltage at the pin. 4 increases from 0 to 2.4 V. This time must be at least 20 ms. Otherwise, IC004 of board A is faulty.
Check for the presence of a voltage of 5 V (commands to turn on the operating mode) on the pin, 2 microcontrollers IC001, on the collector of the transistor Q4, on the pin. 38 of connector CN001 and based on transistor Q604 of board D,
Check for the presence of pulses with an amplitude of 5 V on the lines of each of the two buses! 2C (pin 48 - 51) of the IC001 microcontroller. If there are no pulses on at least one of the terminals, then most likely one of the microcircuits connected to these buses is faulty. These microcircuits are turned off one by one until a voltage of 5 V appears on the bus. The presence of a positive voltage of 5 V on the bus in the absence of pulses also indicates a malfunction of one of the microcircuits. If a faulty microcircuit is found, it is replaced with a known good one.
A malfunction can occur in the IC002 memory chip due to damaged reset circuits. To eliminate the defect, a jumper is installed between the pin. 9 connectors CN001 and housing. Then the following buttons of the remote control are sequentially pressed: “5”, ”- -“, ”5 ″,“ 9 ”, turning on the TV in standby mode, display (“? ”),“ 5 ”,“ VOL + ”,“ on. TV ”,“ 4 ”,“ 9 ”, and then disconnect the TV from the mains.As soon as the red standby indicator goes out, the TV is turned on again. The image should appear, but if after two or three attempts it is not there, then the memory chip must be replaced, and then the necessary adjustments to the geometry, white balance, AGC level and AFC must be made.
The malfunction may occur due to the failure of the tuner and manifest itself as follows. Immediately after turning on the TV, chaotic horizontal stripes appear on the image, accompanied by a crackling sound in the loudspeaker. Then the image disappears, noise appears on the screen and the TV stops responding to commands.
Switching the TV to standby mode can occur by an overload signal coming from the sensor (resistor R608). To check this fact, measure the voltage at the pin. 3 IC602 chips. If it is more than 0.7 V, then the serviceability of the T803 transformer is checked. To do this, disconnect its pin. 4 from the board and turn on the TV. Appeared on the cont. 1 connector CN1201 135 V supply voltage indicates transformer failure. The characteristic signs of its malfunction are as follows: at the moment of switching to standby mode, a characteristic sound of a high voltage surge is heard, the LED flashes 7 times, and then lights up constantly. There is no voltage on the PROT bus.
If all of the above has not eliminated the defect, then most likely the microcontroller is faulty.
The TV does not switch from standby to working. When you try to switch, the indicator LED works cyclically: several flashes - pause
With such a defect, the number of flashes should be carefully calculated, since it indicates a faulty part of the functional diagram of the TV. The relationship between the number of LED flashes with the address of faulty areas and the reference designation of the microcircuits and devices included in them is shown in Table 4.
The CRT screen does not light up. There is no sound. There is a high voltage at the anode
You can verify the presence of high voltage by touching the back of your hand to the surface of the CRT screen. In the presence of tension, a slight tingling sensation will be felt, accompanied by a soft crackle. The static charge generated in this case can also attract a sheet of paper brought to the screen.
The presence of high voltage indicates the serviceability of line scan devices,
It is impossible to imagine a modern apartment or house without video and audio equipment. This equipment is used on a daily basis and therefore breaks down more often than others. There are several ways to repair TVs: send the technician to a service center, call a qualified technician at home, or make repairs with your own hands.
Before you start repairing a TV, you first need to make sure what the problem is. This will also help if you do the repair yourself, and then when the master comes, you will be able to explain the situation to him.
There are several types of malfunctions that can most often be found when a TV breaks down.
- The technique does not turn off. In independence, a CRT TV or a modern LCD model has broken down, this malfunction is associated with a blown fuse. Only different models have distinctive details from each other. You should also pay attention to the diode bridge - perhaps it was he who burned out.
- In both domestic and imported models, the potential can often go astray, for the function of which the posistor is responsible.
- If the plasma TV monitor is broken, then the problem, most often, is interference or drops, light or dark stripes may appear, color changes while watching a program or movie.
- The problem may be a broken cord or a faulty outlet.
If we take into account all the troubles listed above, it is worth saying that the most difficult breakdown is considered to be a screen malfunction.For example, light reflections appear on your monitor after the liquid hits the matrix or the TV is hit, then it is better to carry it to the teleservice. Here it will certainly be repaired, and if the warranty period has not expired, then it will be free of charge or at a reduced price.
See also - How to choose a TV for your home in 2018?
You can try to fix some malfunctions of TVs yourself. And it doesn't matter here - these are LCD models, LCD or LED, it is not necessary to call the wizard if you are confident in your abilities. But caution never hurts, because such TV models are not cheap, and without having any repair experience or knowledge in this area, you can only harm and aggravate the breakdown.
Before you start repairing LED or LCD TVs, you must carefully read the instructions, and also study the principle of operation of your model. Anyone, even one far from this field, will understand that the repair of TVs such as LCD or LED will differ from CRT models. In the latter case, you are guaranteed not to run into a faulty PTC thermistor. The main thing here is to determine the problem, why does the backlight not work?
If you are repairing LCD, LED models, then the only difference here will be what kind of backlight is used. If it is an LCD TV, then the backlighting is produced using fluorescent or fluorescent lamps. For TVs, LED backlighting is produced using LEDs. At this point, the differences between LCD models usually end.
The breakdown can only consist in the fact that there is no power, in order to check this on an LCD TV, you can do the following with your own hands:
- open the back cover of the model;
- remove the wires connected to the matrix;
- connect the working lamp to the contacts;
- there are also LCD models that have more than one light source. In this case, all sources must be tested. Just dismantle the matrix and plug your TV into the network - you can see which LED is the problem.
When a broken lamp in an LED or LCD TV is identified, it must be replaced. This stage requires maximum care from the master, as well as the manifestation of special attention. In some cases, the lamp is removed without removing the matrix, you just need to move the protection elements with a rubber gasket and pull out the lamp with a soldering iron. Similarly, it is necessary to mount a working light bulb. Now we can congratulate you - you did the repair of the LCD TV with your own hands! Just pay attention to one important nuance - the new light bulb must fully meet the parameters and dimensions of the broken one!
To repair TVs yourself, look carefully at the matrix! If there are "unhealthy" streaks here, then the breakage is in the matrix. Have a new part? Then everything is simple! You change it and turn on the TV, if it works, then you have accurately identified the breakdown.
If the reason for the breakdown of LCD TVs is the screen, then it is best to purchase new models of LCD or LED equipment. It is not recommended to change the screen of LCD and LED models, as it is impractical! This also applies to the LCD matrix.
What could be the problem with a malfunctioning plasma TV? If it is necessary to repair plasma TVs, then proceed in the same way as described above. Just adapt it to your specific case. This description can be applied to any model of plasma TV, just stock up on the necessary tools in advance.
Although today most users prefer to use plasma, many still watch programs on more outdated CRT models. Let's find out how to repair a breakdown in such TVs. Below is a step-by-step instruction that will help you repair your electron beam product with your own hands.
- If you do not turn on such a device, check first of all the fuses.In these TVs, the back is made up of panels. Therefore, it is necessary to unscrew that part of the panels. Under such panels you will find a board and the power terminals must be connected to the fuse. They are connected to a conventional incandescent lamp, or rather to its base, after which the TV must be connected to the network. In the event that your equipment is in good working order, the lamp will go out after switching on, otherwise, when the fuse has blown, it will either not work at all, or it will constantly burn.
- The diode bridge may also break. It should only be borne in mind that it is necessary to regulate and repair it only after making a dial. In this case, not only a multimeter is used, but also a product passport, which indicates the main parameters of this model.
- The most difficult breakdown in a TV with a kinescope is a posistor. To make a check with your own hands, you must first turn off the power circuit, and then turn it on. In this case, the lamp must be monitored. If the working lamp goes out, then it can be said that the posistor is faulty. To make repairs, it is necessary to adjust the resistance of the network and only ventures to change this part.
But not only the matter may be in the posistor, transistors and capacitors burn out in CRT models. The diagnosis of this breakdown can also be made visually. If the condensate is blackened or cracked, then we replace it with a serviceable analogue. Now you know why the TV does not work and how to fix it yourself.
The situation when the TV cannot be turned on from the remote control or buttons on the device itself, and the light glows red, is often found in repair practice. 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 repair of the TV.
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 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 without question.
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, unstable power supply leads to the loss of information in the Eeprom, 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.
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 follow 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 TV chassis component repaired.
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.
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. In this case, the backlight turns on, but has a weakly pronounced character due to the underestimated image brightness.
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.
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, 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 the 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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Today we will look at a rather common and commonplace malfunction of TVs, regardless of brand and model.
So, I entered repair lcd tv samsung, which the did not turn on from standby mode.
The indicator light on the front panel glowed red, reacted by "blinking" to pressing the buttons on the remote control, but did not turn on, i.e. remained on duty.
According to the client, this was observed before, but the client tried to turn off the device not with the remote control, but immediately from the network, removing the plug from the socket. But one day it happened that the TV was turned off in standby mode and it did not turn on again.
It is quite simple to understand this television receiver - you need to unscrew the screws located along the perimeter of the rear wall. You also need to unscrew the bolts that secure the stand. After that, the back wall can be easily removed. For caution, I personally carry out the autopsy procedure by placing the TV lying down, matrix down, placing something soft under it.
After removing the cover, the cause of the malfunction of this unit was immediately discovered. In the power supply, in the standby power circuit, two swollen capacitors were visible - 1000 uf 25 V and 470 uf 25 V.
After removing the power supply, replacing the failed capacitors is not difficult, just do not forget that electrolytic capacitors have polarity, i.e. they have plus and minus. Accordingly, they are connected to the board, taking into account the polarity - "plus" to plus, "minus" to minus.
After replacing faulty parts, you need to install the TV power supply in its place, connect the necessary loops and make a test switch.
As you can see in the photo, our device works great - it shows well, and turns on / off from the remote control.
Let me remind you that such a breakdown is very common among TVs of this type, regardless of brand and model.
Good evening! There is an Odeon ltd 1501 TV. It worked without any comments for almost 8 years. And just like in your example, it did not turn on from the standby power. , then the screen is dark, but there is sound. But when the picture appears, at first there is no sound, but then it gradually appears and grows to normal. I'm not very good at this, but I would like to try to patch it up. What can you tell me offhand? ( By the way, this TV set was presented to me for my 60th birthday)
I have not come across such, but "offhand" I recommend checking the TV (after "opening" it) for "swollen" capacitors. Very similar symptoms.
Victor, good afternoon. Thank you for registering. I have the same malfunction on LG plasma - I'll try to find the containers.The question is - is it enough to replace them? Or look further - increased voltage at their input ...? Or did they swell on their own?
Hello, Alexander!
If, nevertheless, the containers are swollen, then you just need to replace them. Capacities swell for several reasons: they are constantly energized (TV is in standby mode and does not disconnect from the network), not very high-quality capacitors, low capacitor voltage rating (usually manufacturers save and put capacitors with a face-to-face value). Replace, preferably, with similar capacities, but slightly higher in voltage. I think it's not worth looking for an increased voltage, since if this happened, then in addition to the capacitors, something else would be out of order.
But if possible, you can check the elements in the harness.
Hello Victor! I have such a problem: the Samsung Le32b550 LCD TV, when turned on, the red indicator reacts, the boot sound is heard, but there is no image, and so it cycles on and off itself, with an interval of 5-7 seconds. I checked the power supply, the conductors are visually alive, but from the power supply output instead of 13V, 12.4V comes out, and the 5.1V outputs are working properly. Can you tell me what is the reason?
good day! is there a Samsung LCD TV does not accept the remote control how to fix it? Thanks!
Well, first you need to make sure that it is faulty - the remote control or the TV itself. The remote control can be tested by pointing it at a mobile phone camera (or any camera) and pressing the buttons. If the remote control is working, then on the phone you will see how its IR LED (peephole) glows when you press the buttons. If the LED does not light up when you press the buttons on the remote control, then it is faulty. If the remote control is working properly, then anything can be on the TV - from poor soldering or dustiness of the TV's photodetector, to the firmware rally. In this case, it is better to consult a specialist.
Hello Victor! I have such a problem: the Samsung Le32b550 LCD TV, when turned on, the red indicator reacts, the boot sound is heard, but there is no image, and so it cycles on and off itself, with an interval of 5-7 seconds. I checked the power supply, the conductors are visually alive, but from the power supply output instead of 13V, 12.4V comes out, and the 5.1V outputs are working properly. Can you tell me what is the reason?
Hello Victor! Well, first you need, after all, to check the capacitors esr with a meter, and if there is no device, then replace it. Check the loops, maybe where they go. And if it reboots cyclically, then, perhaps, the firmware has flown.
Hello! I have such a problem; I turned off the Samsung UE46C7000W TV with the remote control and after an hour I turn on the LED blinking, and I hear that the relay clicks, but it does not turn on, what is the reason, please tell me ..
Hey! See power supply, swollen secondary capacitors and backlight power.
Goy! Hi, I looked, the voltage multimeter rang, everything is normal, but when the relay turns on (the relay clicks), the voltage drops to zero everywhere ..
Hey! It means that he sits down somewhere. See secondary, led driver, backlight. Stubs on the lane.
Before this breakdown, I inserted a USB flash drive with a film, something clicked (like a discharge), but it worked for about five minutes .. can there be static voltage?
Hello Victor, I have a Samsung le26r71b telly, the problem is that I turn it on, it works if you turn it off after ten minutes or more, it no longer turns on immediately and the light on the button starts blinking when you turn it off from the outlet and wait, well, about 10-15 minutes. it turns on and everything works, but when you turn it off, it will not turn on right away until you turn it on from the outlet and again you wait when opening the back cover, two swollen capacitors were found for 1000mfa 35 volts and 470mfa 25 volts replaced them, nothing changed
Hello Ivan! Try replacing all the electrolytes in the power supply.
Hello, Samsung le26a451c1 TV won't turn on. When you try to turn it on, the red indicator flashes, sometimes it can blink for a minute and stop responding altogether to attempts to turn it on, and sometimes it blinks all day until you turn it off from the network. When disconnected from the network, the indicator does not go out immediately.If, after trying to turn it on, it does not disconnect from the network, it can turn on itself at night or after a couple of days.
The capacitors are intact, the loops are all connected. Where to look for the problem
Hello, Tanechka! If you are sure of the capacitors, then you need to look at the secondary circuits, power on-of, BL-ON, inverter, and of course the backlight itself.
Hello Victor! I have the same problem that you outlined. Only a still barely audible click goes. What could be the reason? After reading here, I realized that there are capacitors, but I am confused by the click at the same time. Please tell me .. (LCD TV Samsung TV, remote control BN59-00437A)
The click is probably the inverter trying to start.
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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 required 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 the 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 during prolonged operation and lose capacity, 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 valid. 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.
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