Under what circumstances need to replace the TV backlight?

LCD TVs have been used for a long time, and there will always be big and small problems. The problem we often encounter is LCD TV backlight failure. I believe this term sounds very rusty, but it doesn’t matter. Next, let’s listen to the editor to analyze it in detail. Analysis, you know how to repair the LCD TV backlight failure.

1. The phenomenon of LCD TV backlight failure

Fuzzy screen at power-on I have also encountered damage to the lamp tube in the screen during maintenance; flickering occurs after one time it is turned on, and the sound is normal. This phenomenon is the bad digital board, and the second is the bad internal connection.

There is no image and no sound when starting up. There is no image and no sound when starting up, the power light flashes once and turns into a constant light, and the screen flashes white light when starting up. Causes of LCD TV backlight failure

There are three power-on without power-on three without, and the power light is not on. One is that the power board is broken, and the second is that the CPU part is not working properly; the light flashes and the power cannot be turned on: the CPU bus is not working properly or the boot program IC is bad, which is the BIOSIC and CPU Poor contact between.

2. Causes of LCD TV backlight failure

The backlight is turned off when the LCD screen is on when the AC is turned on. At this time, the audio, remote control, and panel button control functions are all normal. This phenomenon is caused by the backlight circuit protection, mostly due to abnormal power supply of the backlight booster board. For the CCFL backlight circuit, if a certain backlight tube is open (usually the circuit protection caused by the opening of the tube socket on the backlight booster board or the socket is not plugged tightly) or a certain tube break can cause the above failure .

3. Repair LCD TV backlight repair

There is no change in the LCD TV backlight switch machine, sound, remote control, and panel button control are all normal. Then this fault needs to detect the following working conditions: the power supply of the backlight booster board circuit, the common large screen is 24 volts, a few use 120 volts, and the small screen is generally 12 volts; the backlight booster board output by the CPU control circuit The switching control signal of the oscillator is usually a high-level start, and it is mostly a three to five volt lamp lighting control signal. If all the above working conditions are met, the backlight booster board can be replaced. If the backlight booster board is replaced, the failure remains the same, mostly because the backlight tube in the LCD screen assembly is damaged.