Huawei nova 7 SE startup does not display repair

Machine model: Huawei nova 7 SE
Customer description: The mobile phone doesn’t display when it is turned on.Reballing has a display chip, but it doesn’t move anywhere else.
Test results: The mobile phone vibrates when it is turned on, which proves that the machine can enter the system, and the mobile phone is powered on short-circuit current 50ma, but the display screen does not display it.
Fault analysis: mobile phone short-circuit current 50ma, display screen does not display, peers have already bought display chip Reballing, which may be two problems caused by a single fault point,short-circuit current is caused by short-circuit current, and short-circuit current may also be the main reason for non-display. Therefore, the key maintenance direction is around the display chip, but the maintenance still needs to be done step by step. Open Xinzhizao Soft software,Find the annotation map of Huawei nova7se. And find the display FPC BTB connector and display chip.

Huawei nova 7 SE startup does not display repair figure 1.

First, measure whether the monitor BTB connector diode value is normal, and find BTB connector Diode value is normal. After the display chip is removed,short-circuit current is repaired, which proves that it may be Short circuit inside the display chip or Capacitor Short circuit around the display chip. After the display chip is removed,Capacitor around the display chip is measured and an Capacitor with obviously wrong color is found.After measurement, the Capacitor Short circuit was determined. After looking at the drawings, it was found that this was GND Capacitor of a chip.