Originally Posted by frugalfabrics

Might be the power supply box...when mine died, there was a blinking light inthe back of the tower. Mine was still under warrant so they sent us a new one and we in stalled it ourselves.

It involved us taking the one out and putting a new one in once the replacement arrived. It wasn't hard at all.

Hope you can figued out what it is and get back to working on your computer.