I'd go with Nihil. Sounds like a power supply problem. Sounds like this has been a costly problem if you've lost so many HDs. I know it doesn't help but I'd consider salvaging what you can from the box and cutting your losses by getting rid of it. Experimenting to find the problem could cost you more. If you're determined to sort it out, and can live with the cost, then please let us know what you find out. Sorry I can't be aymore help.

Good Luck