Double Click Computers: Common Problems Of Dark Screen And Flickering Screen In ASUS & Lenovo Laptops

Common Problems Of Dark Screen And Flickering Screen In ASUS & Lenovo Laptops

The First One:

ASUS A555L. The fault is a dark screen or flickering screen when using the battery alone. It works normally when connected to the power supply or both the power supply and the battery.The battery charges and discharges normally.

Analysis Process:

If the screen backlight is turned on or the boost circuit is faulty, first disassemble the phone and replace it with a new one to determine if the screen is faulty. I took apart the screen and found the model number is N156BGE-L41.

When the battery is powered on and tested, the boost capacitor is only 8.5V, which is obviously abnormal. BL_EN3.3V is normal. The boost chip uses CM509A. I found the same one in the cracked screen box.

For the boost chip, replace the CM509A boost capacitor after providing heat insulation protection. The normal voltage is about 30V, and the test showed normal performance even with a single battery for one day.

This model has had the same fault repaired on 3 units, and another one was found to be faulty. The customer said it would be repaired as soon as the salary was paid. Maybe it went to your home? I won’t take any pictures of the phone when it’s turned on.

The Second One:

Lenovo FLEX 2-14D, the fault is a dark screen, and the external monitor is normal.

Analysis Process:

The screen backlight is turned on or the boost circuit is faulty. If the screen is disassembled and replaced with a new one, it is determined to be a screen fault. And the screen of this machine has a touch function. When I opened the screen, I found that the model number is B140XTN02.