Huawei Honor 9X Pro cannot be charged and repaired

Machine model: Huawei Honor 9X Pro
Customer description: The mobile phone Camera can’t be lifted and lowered. You can lift and lower it after you remove the two resistors next to U2803. But then the phone can’t be charged.
Test results: all functions of the mobile phone are normal, and there is no prompt for charging when lighting cable is inserted.
Fault analysis: The fault should be in the two resistors removed by the customer.
Open Xinzhizao Soft software, find Honor Honor 9XPro Boardview, and find u2803.

Huawei Honor 9X Pro cannot be charged and repaired Figure 1.

According to Boardview, the customer removed the resistors R728 and R729.

Huawei Honor 9X Pro cannot be charged for maintenance Figure 2.

Huawei Honor 9X Pro cannot be charged and repaired Figure 3.

These two resistors, one end of which is connected to U2803 and CPU, and the other end of which is power chip 1.8V VCC, are signal pull-up resistors. Continue to open schematic to check U2803, and find that the U3803 and CPU lines connected by these two resistors are I2C4 data and CLK lines.

Huawei Honor 9X Pro cannot be charged and repaired Figure 4.

Remove these two resistors, that is, lower the high level of I2C4, which makes it impossible for CPU and chip to communicate, while A1 and C1 pin of U2803 are the CC detection pin bits of USB interface, which makes it impossible to detect after USB is plugged in, which makes it impossible to charge, and makes up 1K resistor for fault repair.