First of all, understand that the common faults of LCD are as follows: White screen, flower screen, black screen, yellowing, white spots, adventitia scratches, color deviation, bright and dark lines, and so on. How to repair the failure of LCD?
First, the maintenance methods of white screen, black screen, yellowing, white spots and so on.
The white screen is mainly caused by abnormal power supply of + 3.3V or + 5V of LCD screen.
The main reason for black screen and dark screen is the aging of CCFL, so just change the lamp tube directly.
Yellow and white spots are the problems of backlight, which can be solved by replacing the corresponding backlight sheet or light guide plate.
Outer film scratch means that the polarizer on the surface of liquid crystal glass is damaged and can be replaced by purchasing a suitable polarizer.
Anti-static treatment should be done during maintenance to prevent damage to large-scale CMOS integrated circuits, and the LCD screen should be protected to ensure that the LCD screen will not be damaged.
Second, color bias:
1. Check the motherboard signal RGB input to the main chip part of the circuit (with or without virtual welding short circuit, capacitance and resistance error).
two。. Enter the factory mode, adjust the white balance, can you bring up the normal color.
3. Replace MCU or re-burn MCU if necessary.
4. Change the line and try to replace it with a general-purpose board to write the program.
Third, Flower screen.
1. Measure whether the motherboard clock output is normal.
two。. Check the motherboard signal RGB input to the main chip part of the circuit (with or without false welding, short circuit, capacitance resistance error value.
3. Check the motherboard signal output to the connection seat part of the output to the screen for false welding, short circuit (IC pin, resistance and seat, double-row pin, pay special attention to the flat socket.
4. Replace the screen or universal driver board if necessary.
4. Bright or dark lines on the screen.
This problem is usually caused by the failure of the LCD screen.
The bright line fault is usually caused by a problem with the wiring connected to the LCD body.
The dark line is generally that the body of the screen has leakage, the above two problems are basically sentenced to death to the machine, there is no maintenance value, and because of safety problems, it is recommended to find a professional.