Chosen Solution
Hi, I always put my iMac on sleep when i am not using it once a time when the iMac was on sleep I heard a strange noise like (zeeee,zeeee,zeeee,zzzzz) it’s like it want to run or do something and it can’t the after half Minutes shows a question mark inside a file
Sounds like your hard drive has failed. Start up from your system installation disk by inserting the disk and starting holding down the “c” key. Go to the second screen pull down menu to Utilities > Disk Utility, and see if you can select the hard drive on the left. If so repair the drive till it runs clear. If not let us know, also if it is still under warranty.
