What was found
BOTH FMCS DROPPED "OFF-LINE" MULTIPLE TIMES DURING PREFLIGHT. BOTH MCDUS ALSO WERE UNUSABLE. GROUNDED - YES. PERFORMED FMCS BITE PROCEDURE, FOUND FMC-L PGM FAULT ONE OCURRENCE AS PER FIM 34-61 TASK 801. PERFORMED FMCS RESET BY OPENING C/B'S A6 (FMCS CMPTR 1) AT P18-2 AND D16 (FMCS CMPTR 2) AT P6-1, WAITED FOR 30 SECONDS AND THEN CLOSED, AND VERIFIED FMC PROMPT SHOWS AT MCDU FOR SYSTEM #1 AND SYSTEM #2, OK TO CONTINUE AS PER FIM 34-61 TASK 807.