What was found
ON PREFLIGHT, AFTER CARGO FIRE TEST INITIATED, AFT 1 DISCHARGE SWITCH WAS FLASHING & CONTINUED TO FLASH. THIS WAS AUTO TEST WHEN IRU'S SELECTED ON AMM, SMP. RESET BOTH MSC CB'S IAW MM 31-42-01-5, RTS PASSED, PERFORMED CARGO FIRE TEST & ALL CHECKS NORMAL. NO HISTORY FOR 90 DAYS, ACFT OK FOR SERVICE. THERE WERE NO CURRENT FAULTS IN MSC PRIOR TO CYCLING CB'S.