G'Day. Hwd406
Long shot, try removing the CMOS battery, (make sure you have unplugged & turned everything off from your system), I usually give anywhere from 1/2 hour to 1 hr.
After which, place battery back in, connect all cables, & power up, keep hitting the Del button while doing this, hopefully this will bring you back to bios.
If you are still having problems, you might have to resort to using the old PS/2 kbd, & recheck the bios settings, maybe for some reason your USB setting for your kbd was set to off for some reason or other.
Ben.