Overhaul Ideas for the Uneven Brightness of LCD Backlight

1. The top is dark and the bottom is bright

Because different manufacturers design different high-voltage boards, their protection principles and detection principles are also different. Since the logic board of the LCD screen also heats up, the two lamps on the upper part generally age faster, and the lower one is slower. Sometimes because the upper lamp tube is aging or sparking and burning, the upper lamp tube is no longer bright, but the high-voltage board is still unprotected and continues to work normally. At this time, what we see is that the top of the screen is dark and the bottom is bright.

2. Bright on the right and dark on the left

Sometimes we will see that the right side of the screen is bright and the left is dark. This is because the lamp is not fully lit, but only part of it is lit. The reason is that the high voltage sent by the high-voltage board is not enough, which is much lower than the voltage that activates the phosphor in the lamp tube. At this time, the phosphor near the high-voltage position will rise first, and the far away part will be completely dark.