Why is there a motherboard problem with Xiaomi K40?

The power management chip is damaged and the motherboard is not powered on.

Symptoms of mobile phone motherboard failure: The symptoms of mobile phone motherboard failure are generally system startup failure, no display on the screen, black screen crash, no boot, no sound, no phone call, no networking and so on. Second, the mobile phone motherboard failure causes: water ingress, falling, unstable charging voltage, etc. The motherboard on the mobile phone integrates all functions such as power supply, CPU, memory, hard disk, display circuit, audio, signal and wireless.