Power Supply Problem?

[BOB IROC]

I am just looking to get some feedback on my personal computer. The other day I shut my computer off before I went to work like normal and when I came home and went to turn it on it hung at the BIOS screen. After about 10 minutes of being really pissed off I just decided to let it be for the evening and use my laptop.

It Has been a couple days and I thought I should tinker around and see what the problem is. So I opened the side of the case and disconnected all unneccessary devices and the problem was still there. The next step I unplugged all of my USB devices from the back and turned it on. There was about a 5 - 10 second delay after hitting the power button before the computer kicked in, but it got passed the BIOS screen and stopped because it saw no hard drives (they were unplugged). I powered down once again and reconnected my internal componants and hit the power button again. There was still a 5 - 10 second delay but the computer booted normally after that and I am writing you on this forum right now using that computer. I am afraid to plug in my usb devices (Printer, Scanner, USB Hub, Zip Drive etc...) as I do not want to risk the thing crashing on me, but the 5 - 10 second delay concerns me a bit and I think their may be a power supply problem. We have had a lot of storms in the area lately and I protect my computers using an APC battery back up, but I may have gotten a hit. I don't know. I am just wondering if anyone feels something else could be the problem like a motherboard or something.

Detailed Computer Specs
ABIT KN8 Ultra
Antec NEO480 Power Supply
Athlon X2 4400+
2GB OCZ PC3200 DDR Ram
2x 120GB Western Digital SATA2 HardDrives
1x 120GB Western Digital IDE hard Drive
1x 60GB External USB2 Hard Drive (Still connected and appears to be working)
XFX GeForce 6600 256MB PCI-e
DVD-ROM and DVD-RW

Any advice or insight is appreciated before I tear this thing apart and start messing around.