First, the main fault of the LCD liquid crystal module
1. Shallow screen during testing
2. Plus the power display is messed up
3. Missing COM (horizontal bars) or SEG (vertical bars)
4. Display None
5. Failure to follow procedures
Second, the LCD liquid crystal module functionality of the reasons are analyzed as follows:
1. The possible reasons for a shallow screen are: PCB board short circuit; short circuit caused by dirty PCB board; short circuit of zebra paper itself, short circuit of zebra paper electrodes at the press screen; press board or press screen electrode misalignment.
2. The possible reasons for the display mess are: bad test tooling; bad PCB board chip; serious misalignment of the pressure plate and pressure screen, zebra paper and board short circuit; zebra paper short circuit.
3. Lack of COM or SEG may be due to: PCB board disconnection; pressure board or press the screen when choking broken zebra paper electrodes, zebra paper itself electrode short-circuit; clearing the screen cut electrodes or the screen itself electrode broken; zebra paper compression at the crack.
4. The possible reasons for the display of no are: bad test tooling; power supply voltage is not normal; test tooling clips are not clamped properly; PCB board is bad; zebra paper compression at the serious cracking.
5. Possible reasons for not going through the program are: problems with the test tooling, power supply and test clips; bad PCB boards.