What was found
DOOR CLOSED AND DURING ENGINE START .EQ COOL EXT FAN 1 AND 2 STATUS MSG AFTER START. ENGINE WAS SHUT DOWN AND MTX ENTERED FLIGHT DECK . AND GROUNDED AC .MTX RE-RACKED LEFT AND RIGHT ECS CONTROL CARDS M861 AND M862, NO HELP. CYCLED EQUIPMENT COOLING SELECTOR SWITCH, VERIFIED BOTH EXHAUST FANS RUNNING MESSAGE CLEANED. ACCOMPLISHED COOLING FAN FIM 21-26FT 851. EQUIPMENT COOLING OPS CHECK GOOD IAW B767 AMM 21-26-00. ACCOMPLISHED BOTH ENGINE IDLE RUN IAW B767 AMM 71-00-00, NO DEFECTS. A/C REMAINS ETOPS 180 .AND RETURNED AC TO SERVICE