hello, I'm new to this but then this is the first time I've had a problem. I have an old imac snow that one night it was fine but I lost power at the house and the next day it would not power up the surge protector it is pluged into is still working and so are other things that are in it. I had someone look at it and was told the main board is dead and it is not worth fixing. my question is if I replace the main board is there a good chance the hard drive is still good. and is there a power unit that might be bad. thanks for any help you can offer.