Hi, I work as field tech for NCR, there is no way to clear the password if it has been forgotten - its designed that way to stop anyone with physical access to the ATM / SCO from booting off other media.
Kinda makes sense in the ATM environment hey
Last thing an ATM needs is the ability to boot off a custom OS with hacking tools.
The password can actually corrupt itself and renders the board useless - NCR dont even repair these if they become bricked, their a throw-away job unfortunately as labor, transport etc cost more than a new board.
I can give you the default (non-customer specific) passwords to try, obviously I cant hand out passwords to try used by the banks. You can try the default passwords of 2468, NCR, NCR123 and NCR456.