DRS GEL, GELMFC & IMA Red LED Lights at Bootup, Major Failure

DRS GEL, GELMFC & IMA Red LED Lights at Bootup, Major Failure No Dig. record available, "System Communication Error" on Advantx Console. DRS powerup test showed: Link bus B failure on the GEL bd.(red LED,ON) Link bus B failure on the IMA bd.(red LED,ON) GEL buffers fail GEL MFC bd.(red LED,ON) Major Fault Detected Diagnostics w/laptop showed failures on GEL1. GELmfc, and IMA boards. (all LINK bus B-acq-mother bd-GEL1 GElMFC and IMA) replacing the boards did not resolve the problem.