IIRC You can just replace the board, there's nothing specific about it to the CNC. There are CMOS settings that must be made in case of battery failure. Don't recall what they are.
Bridge Board can also be replaced at will, no settings are on it. It plugs into a key at the back of the card cage, and that key contains the CNC serial number. The option code for that CNC will look at the serial number key for a match so that config and options are enabled.