B747-400 CAPTAIN QUESTIONS WHETHER MAINT ATTENTION TO FMC ANOMALIES IS ADEQUATE.

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DURING PREFLT IN ZZZ1 WE HAD A MAP SHIFT BTWN FMC GENERATED POS AND RAW DATA OF AT LEAST 4 DEGS DEV FROM ZZZ1 VOR SITTING AT GATE AT INTL TERMINAL. WROTE IT UP ALSO STATING THAT AIR SHOW MAP WAS READING WRONG. MECH'S ACTION WAS TO CYCLE AIR SHOW CIRCUIT BREAKER. I COMPLAINED THAT THIS WAS INADEQUATE ACTION BECAUSE IT DID NOT ADDRESS THE ISSUE IN THE COCKPIT WITH THE NAV INSTS. SUBSEQUENTLY MAINT RECYCLED FMC CIRCUIT BREAKERS WHICH SEEMED TO FIX PROB. MAINT WANTED TO GO WITHOUT AMENDING THE MAINT RELEASE TO REFLECT THIS MAINT ACTION; BUT I TOLD THEM WE WOULD REQUIRE AN AMENDED MAINT RELEASE AS REQUIRED BY THE FOM AND FAR. WE DEPARTED BUT RETURNED TO THE GATE DUE TO ANTISKID FAILURE. DEFERRAL WAS ISSUED AND WE DEPARTED AGAIN. ON APCH TO ZZZ2 RWY 34L ILS; BEING VECTORED; BOTH FMC'S FAILED WITH NO EICAS MESSAGE. THIS WAS VERY DISCONCERTING TO ME AS WE WERE IN TURB AND WX WITH IFR WX AT ZZZ2. I DIRECTED THE FO'S TO RELOAD THE DATA AND I ADVISED ATC; REQUESTED DELAY VECTORS WHILE FO'S RELOADED ALL DATA INTO THE CDU'S. WE LOST RTE; LNDG ALT; AND PERFORMANCE DATA; EVERYTHING; WITH NO EICAS MESSAGE. WE ACCOMPLISHED THIS IN ABOUT 4 MINS AND SHOT THE APCH. LANDED NORMALLY. I SEE IN THE LOG THAT MAINT ACTION WAS TO RECYCLE SOME CIRCUIT BREAKERS AND CLR THE ITEM. I AM CONCERNED THAT WE SEEM TO BE CASUALLY ADDRESSING THESE FMC TYPE ISSUES IN LIGHT OF THE RECENT EVENT AT ZZZ1 INVOLVING ACFT Y; JAN 08. IS THIS APPROPRIATE MAINT ACTION? I HAVE LEARNED THAT THIS ACFT MAY HAVE A HISTORY OF THIS TYPE OF FAULT BUT I CANNOT SAY FOR SURE WITH THE LIMITED RESOURCES THAT ARE AT MY DISPOSAL HERE IN MY ROOM IN ZZZ2.