AIR CARRIER MLG ACFT DEPARTS STATION WITHOUT ACFT EQUIP PROBLEM BEING LISTED IN THE LOGBOOK NOR CONFERRING WITH MAINT REF THE PROBLEM.

Narrative

AS THE FO WENT OUTSIDE TO PREFLT; I ENTERED COCKPIT AND HEARD GND PWR UNIT RUNNING ERRATICALLY (IT WAS RUNNING OUT OF GAS). ELECTRICAL PWR DROPPED OFF THE AIRPLANE AND INERTIAL COOLING WARNING HORNS SOUNDED. I LOOKED TO DETERMINE IF APU OR GND PWR WAS ON AIRPLANE AND FOUND APU SWITCH OFF. GND PWR VOLTS AND FREQ WERE NOT GOOD SO I STARTED APU AND PUT ON BUSSES. ALSO RESTARTED INERTIAL ALIGNMENT. I THEN NOTICED EACH FMC CDU DISPLAYED 'FMC' AND HAD THE AMBER 'FAIL' LIGHT ILLUMINATED. I CYCLED THE FMC BREAKERS OFF A FEW SECONDS AND THEN ON -- NO SUCCESS. I THEN DECIDED TO PWR DOWN THE AIRPLANE COMPLETELY (NO APU AND BATTERY OFF) IN AN ATTEMPT TO REGAIN THE FMC'S. THIS WAS ALSO ACCOMPLISHED WITH NO SUCCESS. AFTER RESTARTING THE APU; ESTABLISHING ELECTRICAL PWR AND STARTING INERTIAL ALIGNMENT AGAIN; I WENT TO GET THE FLT PAPERS AND SIGN THE RELEASE. AT THAT POINT; ABOUT 5 MINS PRIOR TO DEP; I DECIDED; WITH THE OCCURRENCE OF MY FO; THAT IT WOULD NOT BE PRUDENT TO INVOLVE BUF CONTRACT MAINT WITH OUR INOP FMC -- KNOWING THAT THE PLANE CAN BE FLOW PER THE MEL WITH THE FMC INOP. AS WE COMPLETED OUR CHKLISTS AND DEP TIME ARRIVED; I FELT THAT MAINT CTL -- AT THAT POINT IN TIME -- WOULD INSTRUCT US TO OPERATE WITH THE FMC INOP PER THE MEL RATHER THAN INVOLVE CONTRACT MAINT. AFTER A THOROUGH BRIEFING ON FMC INOP OP; WE FLEW TO CLE. FMC INOP WAS RECORDED IN THE LOGBOOK PER MEL AND RADIOED AHEAD TO CLE MAINT. CLE MAINT FOUND FMC COMPUTER MISSING FROM E&E COMPARTMENT.