Xiaomi 11 Youth Edition cannot be charged for repair.

Xiaomi 11 Youth Edition cannot be charged for repair.

Borrow a charging chip directly from another mobile phone of the same model to be repaired. After installing it, it is tested that the charging is normal, indicating that there is something wrong with the original charging chip of this machine, so replace the charging chip.

Machine model: Xiaomi 11 Youth Edition

Fault phenomenon: the customer described that the mobile phone was slow to charge and could not charge.

Xiaomi 11 Youth Edition Can’t Charge Power Maintenance Figure 1

Maintenance process:

After getting the machine and testing, the fault phenomenon is consistent with the customer’s description. When plugging in the charging cable, it is found that the mobile phone has a charging icon, but it does not charge. Remove the motherboard to measure the tail plug small board, and there is 5V input on the tail plug cable seat of the motherboard, and there is no 5V voltage at the side of the measuring charging chip.

Xiaomi 11 Youth Edition can’t be charged. Maintenance Figure 2

Check the circuit diagram of Xinzhizhao software, and the 5V power supply (USB_VBUS_CONN) is renamed as USB_VBUS after voltage protection MOS tube Q5501 on the drawing.

Xiaomi 11 Youth Edition Can’t Charge Power Maintenance Figure 3

It is measured that the MOS tube has a voltage of 5V at the end of the plug-in, but there is no voltage at the end of the charging chip just now, which means that the Q5501 tube does not work with 5V voltage to the charging chip, causing no charging.

Xiaomi 11 Youth Edition can’t be charged. Maintenance Figure 4

Directly remove the overvoltage protection tube Q5501, short-circuit the input and output pins with the wire tube, and plug in the charging wire to test that the charging chip has 5V power supply, but the mobile phone still can’t charge.

Xiaomi 11 Youth Edition can’t be charged. Maintenance Figure 5

At this time, I can’t confirm whether the charging chip is good or not. I borrowed a charging chip directly from another mobile phone of the same model to be repaired. After installing it, I tested that the charging was normal, indicating that there was something wrong with the original charging chip of this machine, so I replaced the charging chip.

Xiaomi 11 Youth Edition can’t be charged. Maintenance Figure 6

Replace the charging chip, plug in the charging cable, and measure the charging current to be 1.8A The fault is repaired, and the maintenance of Xiaomi 11 Youth Edition is over.

Xiaomi 11 Youth Edition can’t be charged. Maintenance Figure 7