If Ctrl-A-A doesn't work there are three possible causes:
- one of the keys is dead (check Ctrl in a shell window: Ctrl-M is , Ctrl-I and so on)
- the line from keyboard to mainboard is dead - check with a multimeter
- the line from the keyboard connector to the rest of the board is dead - check by powering up with disconnected keyboard and short pin 3 to ground; if Amy doesn't reboot, you've found the problem
