I recently installed new ram into my year old 2.16 ghz intel 20" late 2006 model iMac, upgrading from 1 gb to 3gb. I installed the ram and all seemed to be well. The computer was faster and i was no longer using most of my memory. A week later i went to use my iMac and take it out of sleep display which it resorts to after a period of inactivity. The iMac would not respond. This had happened the day before as well, and a simple reboot fixed it, so i didn't panic. I rebooted it and it didn't respond. The power light lit up, and you could hear something whirring on the inside, the fan or the hard drive, or both, but nothing came up on the screen. After a few minutes of being on, the computers screen would turn the white color it is upon start up when the apple logo shows, but the apple logo never showed up and the loading indicator didn't appear. I've tried reinstalling the ram, and putting in the old ram. I've tried booting from the install dvd. Whatever I try, nothing works. Does anyone here have any suggestions as to what could be wrong?