Lately I've been using an old computer (P133, Gigabyte GA-586HX) that I built new back in university as my retro dos computer. I pulled it out of my parent's basement earlier this year, and while it worked fine, the case was a yellowed, beaten-up, rusty mess. So I recently acquired a very nice new-in-box AT tower case, complete with power supply and a 3-digit turbo display for $20 and proceeded to move the gubbins from the cruddy old case to the shiny new one. I turned it on, and it started up and ran fine except for one major problem.... the keyboard doesn't work. The computer recognises that there is a keyboard attached as I don't get any post errors. The keyboard lights work. If I press the num lock the keyboard light turns on and off. But the computer does not acknowledge any key presses. I can't even press DEL to enter the bios. I've tried several different keyboards with the same result, and I've tried removing everything possible, re-seating the memory, etc. I can't see any obvious problems with the thing.

Before I dismantle the whole thing and start going over the motherboard with a magnifying glass and a soldering iron (I was thinking of re-soldering the keyboard port), I figured I would ask if anyone can think of any stupid obvious things I may have overlooked. Any ideas?