Keyboard woes

There are a couple of things that could cause this problem, but the first thing to do, in your case, is to try another mouse. With two keyboards acting the same, it is very unlikely that either of them is causing the problem. If you are using a PS/2 style mouse (with a 6-pin mini DIN connector), the keyboard and the mouse are actually connected to the same interface. A failed mouse can cause a keyboard not to work in this situation.
Another possible cause of this kind of problem is a brokenor loose keyboard connector on the motherboard. To repair this usually requires removal of the motherboard and re-soldering the contacts to the keyboard connector. If neither of these fixes eliminate the problem, then the third and least likely cause could be a failed or loose keyboard BIOS. If the keyboard BIOS is a separate removeable chip, sometimes re-seating it will eliminate the problem. If the keyboard BIOS is integrated into the motherboard chipset, replacing the motherboard would be the only solution. Good luck.

It sounds like you have the mouse & keyboard connections swapped over, try reconnecting the keyboard where the mouse is connected & the mouse in the other connecter.
Does the keyboard respond to del or F1 to enter the bios?