So I have a 24" iMac that's probably about 2 years old, and the last couple weeks it had intermittently been restarting itself for apparently no reason. That only happened a couple times, but finally it did it and then stuck at the blank gray screen with the light flashing in sets of 3 for some reason. I restarted it quite a few times, and only once it actually booted up to the desktop but after about 10 minutes it went back to a blank gray screen with the light flashing. Any advice on what to do? I had a time machine backup so I already have my data on this new iMac but would like to get the old one working again. Should I try to reinstall a time machine backup, or is the hard drive probably dead? Thanks!