USB missing-or not

[atsa2]

Don't post very often but thought I'd put this out to see if other brains than mine can come up with solutions to what currently has me tearing my hair out.

My PC is a Gigabyte GA-MA78G-DS3H, with Phenom 8450 Triple-Core, 8GB of RAM, 5 HDD running Windows7 Professional 64 bit, 630w Hiperpower psu. All has been running fine since Jan 2009.

The problem is a few weeks ago I had my Android phone (HTC Desire) plugged into one of the front USB ports to charge when something updated & required a restart. Without thinking I let it. The reboot got as far as the bios splash screen, and after 10 minutes or so I pulled the plug. The next boot was fine, but I soon became aware that all was not well...

Since then my USB ports have been flaky. (This motherboard supports 12 USB ports-4 on board & 8 via headers-and all of these were connected.) If I used the front ports then whatever I connected was not recognised, and on a shutdown it would hang then restart to tell me Windows had recovered from a serious error.

I have tried replacing the USB drivers, removing all USB devices from device manager and letting Windows redetect, and even a clean, fresh install of windows 7 on a blank hdd, all with differing levels of failure. The last failed plan was to disconnect all header cables and just use the on board ports at the rear. I have managed to get all/some ports working at some time, but they do not survive a shutdown/reboot and currently I have no working USB ports at all. I am assuming a voltage surge occurred at some time during the first restart, but don't know if it has damaged the motherboard the psu or both, and I'm hoping that someone will be able to come up with a diagnostic that will let me identify the faulty culprit.

Assuming that at least part of the motherboard is faulty, a replacement gives me another problem. I use a KVM to control 3 computers with one keyboard and mouse-both PS/2, and many of the current motherboards have only one port for keyboard OR mouse.

Any solutions/suggestions gratefully received, and Merry Christmas.

[Scrubbs]

the only thing I can think of at the moment is utilize one of the other 2 computers you are running to swap out psu etc from one pc to another, Time consuming I know but it should only cost you time.
Just spotted a Gigabyte GA-MA78G-DS3H on ebay for £40

[Rob]

Always worth checking for any BIOS updates.

[Taf]

If I leave my Flip camera plugged in to the USB of the PC and reboot, I get the same sort of problems. Normally it sorts itself, but a couple of times I have deleted all USB ports in Device Manager and let Windows find them again... then all is OK again.

[atsa2]

Thanks for the replies.
Forgot to mention I'd managed to update the bios through windows, no change there.
New symptom is instead of going into sleep as before, pc just powers off! Haven't seen what happens, but from startup messages seems like power is just cut. Starts up again ok but I'm wondering if this points at psu?
Luckily I'm back at work on Boxing Day so not due to lose a lot of surfing time
@Scrubbs-hadn't thought of that, might be an option with one of them, other psu is too old for atx connection...