LCD TV backlight failure how to repair LCD TV backlight failure repair method

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

LCD TV backlight failure

1. LCD TV backlight failure phenomenon

1. Spoiled screen when booting

In the maintenance, I also encountered that the lamp in the screen was damaged; the screen appeared to be blurred after turning on for an hour, and the sound was normal. The first reason for this phenomenon is that the digital board is bad, and the second is that the connection inside the machine is not well connected.

2. No image or sound when booting

There is no image and no sound when starting up, the power light flashes once and becomes steady on, and the screen flashes white light at the moment of starting up. This fault is mostly caused by the damage of the backlight driver board.

Causes of LCD TV backlight failure

3, start three no

The first is that the power board is broken, and the second is that the CPU part is not working properly; the light flashes and cannot be turned on: the CPU bus is not working properly or the boot program IC is bad, and the contact between the BIOSIC and the CPU is bad.

Second, LCD TV backlight failure reasons

The backlight is turned off when the LCD screen lights up once the AC power is turned on. At this time, the sound, remote control, and panel button control functions are all normal. This phenomenon is caused by the protection of the backlight circuit, and the reason is mostly the abnormal power supply of the backlight booster board. For the CCFL backlight circuit, if one of the backlight tubes is open (commonly, the circuit protection is caused by the lamp socket on the backlight booster board being unsoldered or the socket is not tightly inserted) or a certain lamp is broken, it can cause the above faults . ,

Repair LCD TV Backlight Repair

3. Repair LCD TV backlight repair

There is no change in the switch of the backlight of the LCD TV, and the 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, very few use 120 volts, and the small screen is generally 12 volts; the backlight booster board output by the CPU control circuit The switch control signal for the oscillator to work is usually a high-level start, and most of them are three to five volt lamp lighting control signals. If the above working conditions are met, the backlight booster board can be replaced. If the failure remains the same after the replacement of the backlight booster board, it is mostly because the backlight tube in the LCD screen assembly is damaged.