Xiaomi 11 Youth cannot be charged,How to repair

Machine model:Xiaomi 11 Youth

Fault phenomenon: the customer described that the mobile phone was charging slowly and could not be charged.

Xiaomi 11 Youth cannot be charged Figure 1.

Repair process: after getting the machine for testing, the fault phenomenon is consistent with the customer’s description. When inserting the charging wire, I found that the mobile phone has a charging icon, but it can’t be charged.

There are 5V inputs on the charging connector small board and the main board charging connector FPC, but there is no 5V VCC on the side of the measuring charging chip.

Xiaomi 11 Youth cannot be charged Figure 2.

Check that schematic and 5V VCC are renamed USB by MOSFET q5501 on the drawing_VBUS after charging chip.

Xiaomi 11 Youth cannot be charged Figure 3.

There is 5V VCC at the end of MOSFET connecting with charging connector, but there is no VCC at the end of the charging chip just measured, which indicates that q5501 MOSFET is not working, and 5V VCC is not charging the charging chip.

Xiaomi 11 Youth cannot be charged Figure 4.

Remove the over-voltage Current protection tube q5501 directly, input and output pin with line MOSFET short-circuit, plug in the charging wire to test whether the charging chip has 5V VCC, but the mobile phone still can’t charge.

Xiaomi 11 Youth cannot be charged Figure 5.

At this time, we can’t confirm whether the charging chip is good or not. We need to replace it with a new charging product. After installing it, we test that the charging is normal. It indicates that there is something wrong with the original charging chip of this machine. After replacing the charging chip, the fault is repaired.