I bought a used iMac G5. The computer is no longer powering on. It is one of the models where apple had the 3 year extension with logic board problems, but I don't know the exact purchase date as I bought it used. Are there any tests that I can do in order to find out what is wrong? Or should I just take it to apple and hope they will honer the 3 year extension. On a side note, every once and a while I will get the light on the front that shows it's getting power, but after unplugging and replugging from the outlet the light no longer shows up. Any suggestions would be much appreciated.