Huawei’s glory 9X Pro mobile phone is not charged for repair

Huawei’s glory 9X Pro mobile phone is not charged for repair.

Machine model: Huawei Glory 9XPro

Malfunction: the phone does not charge.

Maintenance process:

I received a Huawei Glory 9X Pro. The fault description shows that the camera of the mobile phone can’t be raised or lowered. After I removed the two resistors next to U2803, it can be raised or lowered, but then the mobile phone can’t be charged.

When the phone is turned on, all functions of the phone are normal, and there is no prompt for charging when the data cable is plugged in.

Open Xinzhizhao, find the glory 9XPro bitmap, and find u2803. According to the dot bitmap, the resistors R728 and R729 were removed.

Huawei glory 9X Pro mobile phone does not charge maintenance Figure 1

The two resistors, one end of which is connected to U2803 and CPU, and the other end of which is powered by 1.8V power chip, are signal pull-up resistors.

Continue to open the schematic diagram and look at U2803. It is found that the U3803 and CPU lines connected by these two resistors are the data and clock lines of I2C4.

Huawei glory 9X Pro mobile phone does not charge maintenance Figure 2

The removal of these two resistors, that is, the high level of I2C4 is lowered, which makes it impossible for the CPU and the chip to communicate. The A1 and C1 pins of U2803 are the CC detection pins of the USB interface, which makes it impossible to detect the USB after it is inserted, so that it cannot be charged. Make up 1K resistance and repair the fault.

Huawei glory 9X Pro mobile phone does not charge maintenance Figure 3

Huawei glory 9X Pro mobile phone does not charge maintenance Figure 4

The failure that the previous camera can’t rise and fall has nothing to do with these two resistors at all. It’s just the dust accumulation on the camera.