Sharp 65S3 backlight is not bright.

The reasons for lamp failure are as follows: 1. The lamp tube is disconnected (the normal computer will not burn out or disconnect the lamp tube because of high voltage, and the main reason for the disconnection of the lamp tube is that the computer falls into the underground lamp tube and is seriously hit) _. 2. The high-voltage package does not supply power to the lamp tube (the motherboard has 3-4 groups of voltages supplied to the high-voltage package, which is supplied to the lamp tube after the chip is reformed, so there is no power output because the chip is aging or burnt out due to excessive current). 3. The motherboard has no electricity to supply to the high-voltage package (the motherboard has 3-4 groups of voltages to supply to the high-voltage package, and the motherboard has 2 groups of chips to output voltages to the high-voltage board, and the chips are aged or burnt out due to excessive current, so there is no electricity output) _. 4. Disconnect the connecting wire (there is a connecting wire between the motherboard and the high-voltage package, and the connecting wire is disconnected after the LCD screen moves for a long time, resulting in no main power supply for the high-voltage package).

The above four points are the main problems that cause the screen to darken. The first three points appear more frequently, and the fourth point appears less frequently. Because the connecting wire is covered with a special shielding wire, the phenomenon of disconnection of the connecting wire is less. It is essential for professional maintenance personnel to check every working procedure.