Received a repair customer lenovo think PAD E40, press the power button did not respond to a test, the next is adjustable power supply test, normal standby, press the power button is still no response,

Next teardown motherboard and get the board look carefully, there is no obvious damage, play value, there were also no significant short circuit test is damaged, this is where the problem

Wanted to think, this part EC machine easily into the liquid, so the tear insulation paper, indeed as expected corrosion

Next, clean, due to recent new iPhone tablet maintenance business, also bought a microscope, the below show, without a magnifying glass, microscope directly, have the obvious break line

Then pick a good break, mend green oil, electricity testing, to boot

Bright screen, installed the machine test OK, machine repair.