The GVRI/O Mini PCB relays all signals between the system computer and the controls. Each connector on the PCB is keyed to fit only to the correct harness connector. Five versions of the PCB exist at the time of this writing, but version 03 is not recommended for these games. Versions 00, 01 and 02 of the PCB have two 5 Amp fuses that protect the coin meter power only. Jumpers must be installed at J5 – Mode Select to put the PCB in Keyboard Mode. For PCB versions 00 and 01 place a jumper across pins 4 & 5. For all other PCB versions place a jumper at position 2.
Caution: Disconnect the cabinet from AC power before changing the fuses or making any connections to the PCB.