|So you are saying your caps lock is on and you can't shut it off? |
Plugging in a PS/2 keyboard while under power can ruin the PS/2 port. I don't know if you did that or not.
Are you using an adapter on a USB keyboard to connect to the PS/2 port? Do you have the keyboard connected to the Green PS/2 port?
If not of the above apply look at the link below.