Faulty component question..

[anandandand]

Hey guys, I'm having some problems with my pc. It's a p4 2.4 w/ 512 ram, radeon 9700pro, audigy 2, 2 dvd drives, 2 hd's, asus mobo. It had a 400w future power ps in it and that died before x-mas. I brought it to a local shop, where that was replaced with a 350w antec ps that worked fine, but emitted a loud, high-pitched wail when turned on. So I brought it back and we started troubleshooting the wail. The tech tried a 400w generic power source on it and that ps fried right in front of my eyes as soon as it was turned on. All the drives were disconnected when this happened and the guy told me that, for this reason, the problem could be with the vid card, sound card, mobo, ram, or cpu.

He recommended that I dump all these components, because the amount of labor time it would cost me to have him troubleshoot the pc until he found the faulty component just wouldn't be worth it.

So I have three options:
1. Pay at least $200 in labor to find the faulty component, and hope the expensive stuff is still good.
2. Replace the mobo, cpu, ram, vid/sound cards, hope that my drives are good.
3. Build a whole new box.

Could the faulty component (whatever it is) have tainted other parts of my system? Should it be scrapped? Internet, please give me your opinion on the matter.

Also.. My hard drives are going on 3 years old but run flawlessly.. should they be replaced in a new system or just swapped in?