773 G-series BICS Controller

after running down all possible wires,grounds,connectors,and checks for fuses and relays,I still find that my non-functioning overhead left and right instrument panels just wildly flash and beep for about 5 to 10 seconds then go off leaving nothing powered. The hour meter says "input" after the panels shut down,which according to the manual indicates that "The controller is not communicating with the left instrument panel" those are the exact words the manual states. So,looks like controller problems. Anyone know where I can get one,if I decide to go that route? Thanks

773 G-series BICS Controller