I have a brand new 250 GB hdd. it is a internal drive but I maid it external, make a long story short I powered it up with it setting on top of my pc, circuit board down. Needless to say a dumb move, the board is fried and I was wondering if I could replace it
is not your pc's top flat because i had 1 of my drives ontop of a customer's pc with no problem with the hd's circuit board down?
I have previously swapped PCB's on HDD's before, but this only works (and even then it is rare) if both PCB revisions and on board firmwares are the same. Needless to say when you purchase up to 8 HDD's at the same time (like I do at work), they usually are identical, but the chances of you getting another drive with identical PCB / firmware revisions are minimal. Have you tried plugging the drive directly into the IDE / SATA channel on your M/B? I would only suggest this if you have an older PC to try it on as if the drive PCB is damaged, you may draw too much current from your onboard drive controller and damage the M/B too. Best case scenario is that you have damaged the USB port (or whatever external port was used to connect the HDD) and the drive will still function. Worse case scenario (as you have already pointed out) is that its fried. Let us know how you get on.
