Xiaomi K40 can't be turned on

Xiaomi K40 can’t be turned on

Machine model: Xiaomi K40

Malfunction: Xiaomi K40 can’t start the machine.

Repair process: Press the power-on button after getting the phone, but the phone doesn’t respond, so it can’t be turned on.

Xiaomi K40 can’t be turned on Figure 1.

The startup current of the power line for repairing the machine is set at about 112mA. This phenomenon should be that the CPU is not working normally.

Xiaomi K40 can’t be turned on Figure 2.

There is a common problem of CPU virtual welding in Xiaomi and Redmi models. CUP virtual welding usually leads to the automatic restart of the mobile phone with bright Logo, or the mobile phone can’t be turned on. Then disassemble the machine and take out the motherboard, remove the temporary storage and CPU, replant the tin, and weld the CPU and temporary storage back to the motherboard.

Xiaomi K40 can’t be turned on Figure 3.

Xiaomi K40 can’t be turned on Figure 4.

After that, put the motherboard back into the mobile phone, restart the test, and the Xiaomi K40 can boot into the system normally. The fault is perfectly repaired, and the maintenance is over.