TV receiver failures, like with any other electronics, can be caused by a variety of reasons, which can sometimes be difficult to get to detect. Both new devices and those that have been in use for a long time are susceptible to malfunctions. For example, trying to turn on your TV receiver, you see the lights flashing, and hear a clicking sound, but the TV still does not turn on and does not work. Different models of units may have different "symptoms". In fact, there may be many reasons why the TV does not work.
If the light is on all the time, it means that the TV is receiving power. When you cannot switch on your TV with the remote control, it is worth repeating the procedure from the main panel. It is quite possible that the problem lies in the remote control. If the equipment turns on, you need to check the remote control.
Diagnosis of DPU:
The batteries in the remote control may have been depleted. When the LED on the transmitter glows bright enough and looks undamaged, you should bring the remote control close to the main panel and try to turn on the TV. If this succeeds, the batteries should be replaced with new ones.
When the indicator light is red, it is likely that the equipment is in standby mode. If you cannot turn on the TV, it is worth checking the main board. It is necessary to inspect all capacitors for bloating and replace them, if necessary, and then make a test run of all the elements. It is also useful to check the power supply by means of the same multimeter.
If a short circuit occurred, or one of the burned-out elements caused the AT24 memory chips (Eeprom, SpiFlash), then a software update is required. When software installation by the local interface is not possible, it is necessary to perform a firmware upgrade with the help of a programmer.
If there is nothing wrong with the main board, but the TV cannot be turned on, you should check the power circuits on the motherboard. There are voltage converters, DC-DC modules, and other secondary sources. The first thing to find out is the stability of the power supply in the given voltage range. The board is diagnosed with a multimeter.
Upon receiving a signal from the remote control, the processor commands the executing elements to come out of hibernation mode and turn on the equipment, displaying a corresponding notification on the main panel. That is, the indicator changes color to green from red.
If the notification LED on the control panel switches back to red, however, it means that one of the circuits is not executing the given command. The problem here could be an inverter that is unable to turn on the backlight, or a faulty power supply blocking the start-up of the equipment.
The processor in such cases switches to standby mode: the LED is red without blinking. For example, the processors of some Sharp brand TVs put the system into a complete lockout after five attempts. That is, the TV cannot be turned on without resetting all settings through the service menu or a complete reflash of the AT24 memory. Other models perform a self-diagnosis when attempting to start until the cause of the fault is eliminated.
There could be many reasons for this. Probably, the logical processes are broken due to an accidental power failure at the moment of their execution. First of all, you should try to force software updates with the help of a programmer. After reflashing the logical processes should return to the normal sequence.
Next, it is necessary to check the operability of the main board: check the main elements, make sure the voltage is sufficient and stable, as well as examine the backlight parts. If there is no image on the screen, but there is sound, then most likely the cause of the failure is the inverter or the LED block, which is responsible for the power supply.
Sometimes the motherboard blocks the reception and transmission of all signals to the controllers or sends incorrect commands that leave the matrix inactive. The latter may also be faulty.
Ultra-budget models are not usually equipped with adequate TCON chips. They receive commands from the video controller and are responsible for signal conversion for the LCD matrix. In some cases, it helps to reflash the chips with a glance at the specifics of the main board of the TV.
When the LED lights chaotically: blink with different frequencies or go out for a few seconds, and then turn on again, but in a different color, it is difficult to identify the cause of the malfunction. Then you need a complete diagnosis of the equipment.
It is best to start with the power supply and then move on to the main board, checking all the circuit elements one by one.
You should also examine the interfaces for connecting third-party peripherals. Occasionally, a short contact on one of the ports blocks the entire system.
If the LED is not lit at all, the problem is most likely in the power supply. It is a good idea to check the functionality of the TV without looking at the LEDs. It is possible that the LEDs have simply burned out. In other cases, it is worth considering the following causes.
There are times when the TV set beeps when you turn it on. When you hear the whistling sounds after turning it on, this indicates a faulty PSU (power supply). Capacitors that have lost capacity can cause this sound. After some time of operation, the sound may become constant, which is a sign that the PSU is about to break down.
If your LG TV does not turn on and starts beeping, you will need a more serious repair of the unit. Such trouble can also visit the TV set BBK, Sharp, Bravia, as well as Toshiba. Whistling can then be caused by a load in the secondary circuits due to:
The Philips TV may not turn on the first time after you haven’t used it for some time. It takes 3 to 4 minutes to turn the TV on, and it can take 10 or more attempts. In this case, as soon as the image begins to appear on the screen, it emits a click and turns off. Such symptoms are inherent in Sharp, Thomson, and Daewoo devices. All of this indicates a malfunction of the power supply capacitors. After turning on the power, due to insufficient capacitance of the electrolytes, the Phillips PSU goes into protection.
The blocking picture can often be observed in a Toshiba TV, and it does not matter whether it is an LCD or plasma TV. It happens in the following way: the turned-on unit shuts down and locks after 3-4 seconds, and in the upper left corner the circle starts to burn. To solve the problem, you must first measure the voltage on the motherboard. If the readings are normal, all you have to do is to reflash the software.
When you turn on the receiver, you see the SmartTV splash screen, the LED blinks 5-6 times and the device "hangs". After that, the Samsung TV does not turn on from the remote control or the panel. There is a response only when you press the button to turn off the remote control (the red indicator blinks), but the TV won’t turn off. What to do? Then the only thing you can do is to de-energize the unit.
Sometimes the TV won’t show the image due to a malfunction in the software shell – you will need to reflash it in the service center. In rare cases, such symptoms can be observed if the CPU, or rather its memory module, is faulty.
This strange behavior has been noticed with televisions. The device can spontaneously stop working after a certain period. Or on the contrary, the TV turns on without anyone's involvement. The cause of the shutdown can be a faulty power control board. Also, the failure of the control board can be another reason. Spontaneous switching on of the receiver can happen:
Sharp receivers have also been found to turn on spontaneously, after which it shuts down and the indicator light starts flashing red. The problem is the same – the power supply or the power board.
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