Second: When encountering this problem, don't unplug the power blindly! This will damage the hardware! As long as you press and hold the on key on the chassis for 3-5 seconds, the computer will automatically shut down!

Third: the computer buzzes after the black screen, which may be that the hard disk is not working properly! Probably the hard disk is not placed smoothly, pay attention to the cable. Another is the aging of the hard disk.

Fourth: cpu is not working, maybe the boss has no electricity, change the battery!

Fifth: This situation has little to do with the motherboard.

Sixth: it can't be a battery short circuit.

Seventh: Did you buy a second mobile phone? If so, it is not surprising that these problems arise. If it is a new machine, change it!

Eighth: If it is a machine that you have used for a long time, then the main problem lies in the hard disk, which is old! It is time to change! If it really doesn't work, fix it.

Check the memory and refresh the graphics card.