Help - G4 17" MacBook Keyboard Problem

[GGD]

Maybe first take a close look at the keyboard to see if any key might be stuck down (press and release each key), maybe one of the modifier keys like FN/CTL/CMD/NumLock/etc are stuck.

Reset PRAM by holding down CMD-OPT-P-R (might need to do that from the USB keybaord). This Apple page has much more detail

http://support.apple.com/kb/HT1379

Since you can get into Open Firmware from the USB keyboard you might try the commands they suggest for that

0 > reset-nvram
Press Return
0 > reset-all
Press Return

http://support.apple.com/kb/TS1812?viewlocale=en_US