Huawei nova 5i Pro can't start the machine for maintenance when it enters the water.

Huawei nova 5i Pro can’t start the machine for maintenance when it enters the water.

Machine model: Huawei nova 5i Pro

Fault phenomenon: the mobile phone can’t be turned on when it is flooded.

Maintenance process:

This mobile phone can’t be turned on when it is flooded. When the machine is disassembled and the motherboard is taken out, the single board is powered on, and the current jumps around 5mA, indicating that there is a short circuit in the main power supply.

Huawei nova 5i Pro can’t start the machine when it enters the water. Maintenance Figure 1

Under the microscope, several black capacitors on the motherboard were observed. After removing the capacitors, the fault remained.

Huawei nova 5i Pro can’t start the machine when it enters the water. Maintenance Figure 2

Smoked rosin on the motherboard, connected the main power supply to a 4V burner, and found that the smoked rosin on the two diodes melted, indicating that the diodes were short-circuited. After deducting the diodes, the power leakage was 50mA, indicating that the motherboard was seriously short-circuited and there was still a small leakage problem.

Huawei nova 5i Pro can’t start the machine when it enters the water. Maintenance Figure 3

Huawei nova 5i Pro can’t start the machine when it enters the water. Maintenance Figure 4

Continue to connect the main power supply to the 4V burner, and feel that the power supply chip and WiFi chip are slightly hot. After removing the main power supply and WiFi chip, the power-on test motherboard is in normal standby, and there is no leakage.

Huawei nova 5i Pro can’t start the machine when it enters the water. Maintenance Figure 5

After replanting the main power supply and WiFi chip, the mobile phone can be turned on, but the sound of the mobile phone is abnormal after turning on, and there is no WiFi and Bluetooth, so WiFi and Bluetooth are normal after replacing the WiFi chip.

Find the audio chip with Xinzhi software. After replacing the audio chip, test that the sound of the mobile phone is normal, and all functions of the mobile phone return to normal. The maintenance is over.