Yesterday I was running my iMac importing tv shows to put on my iPad when we suddenly got an unexpected power outage. When I tried turning it back on it got as far as the start up chime and a grey screen then shut off. I tried ejecting the disk before it shut off one time as the disk is not mine and then it wouldn't even get to the grey screen. I tried a number of troubleshooting tips and now it only puts of a dim high pitched noise. This is about the 4th time this has happened because of a power surge and each time I had to get costly repairs preformed on it. Please help me!!