Consumers comes with Acer 4315 dead. He said the LED blinks when the charger is plugged. The first analysis is a short circuit occurs. The first step has taken is, of course, remove the mainboard. The next check is there any hot components. This is an easy way to find a short circuit.
See in the picture if the components in the box on the pic 1 was hot. Check the capacitors on the pic 2, replace if shorted. Remove capasitor one by one and then check with multitester.