Huawei Mate 20 Pro card logo does not enter the system (CPU virtual welding)

Huawei Mate 20 Pro card logo does not enter the system (CPU virtual welding)

[Fault model] Huawei Mate 20 Pro

[Fault phenomenon] Card logo does not enter the system.

[Maintenance process] I received a machine sent by a customer for repair, the model is Huawei Mate 20 Pro, and the fault is that the card logo does not enter the system.

Huawei Mate 20 Pro card logo does not enter the system

Huawei Mate 20 Pro card logo does not enter the system figure 1

Take the machine and directly remove the motherboard and power it on to see the current. The current can normally jump to 300mA and then drop to 165mA, which is usually caused by virtual welding of CPU. Let’s try it again directly.

Huawei Mate 20 Pro card logo does not enter the system

Huawei Mate 20 Pro card logo does not enter the system figure 2

After the CPU boot test, the current can jump normally, and the screen can be turned on directly, and the test can enter the system.

Huawei Mate 20 Pro card logo does not enter the system

Huawei Mate 20 Pro card logo does not enter the system figure 3

[Maintenance Result] Install the motherboard into the shell.mobile phoneIt can be turned on normally, and the functions of WiFi, Bluetooth, voice, charging, fingerprint, taking photos and making phone calls are all normal, so the maintenance is over.