Huawei Nova6 5G no serviecs repair

Fault model: Huawei Nova6 5G
Malfunction: The machine is water damage, slightly corrode, and the mobile phone no serviecs is turned on, and the operator can be found. The peer repaired it for a day and found no problem.

Huawei Nova6 5G no serviecs repair figure 1.

Fault analysis:water damage no serviecs, check pin and VCC at the bottom of each chip of power amplifier, and the details.
Maintenance process: first observe that the motherboard is not serious corrode.

Huawei Nova6 5G no serviecs repair figure 2.

My colleague told me that there is a HI6421 power supply in the lower left corner of the motherboard, and corrode in the upper left corner.

Huawei Nova6 5G no serviecs repair figure 3.

Open the Xinzhizao Soft drawing.

Huawei Nova6 5G no serviecs repair figure 4.

It was found that this power supply was supplied to the signal chip VCC, and the Capacitor 1.8V of corrode was measured as 2.4V when it was turned on. This circuit was connected to the main board signal chip, the upper board and the charging connector small board.

Huawei Nova6 5G no serviecs repair figure 5.

The VCC is restored to 1.8V through direct boot test without installing a small board.

Huawei Nova6 5G no serviecs repair Figure 6.

Remove the ground filter on the small board, and the fault remains the same. The VCC is still 2.4V before.

Huawei Nova6 5G no serviecs repair figure 7.

Huawei Nova6 5G no serviecs repair figure 8.

According to the 1.8V circuit on the main board, the corresponding pin bit of BTB connector was found, and a connected chip with slight corrode was found in the lower left corner of the small board.