What was found
IN FLIGHT, MICROWAVE MADE A LOUD BANG WHILE IN USE. IMMEDIATELY FOLLOWED BY AN ELEC SMOKE ODOR IN CABIN. FA REPORTED MICROWAVE CB LOCKED. MICROWAVE SHUTDOWN AFTER BANG, ONLY FUMES. R & R MICROWAVE IAW SMM 25-30-66. PERFORMED OPS CHECK, COULD NOT GET CPB'S TO UNLOCK. ONCE IN ON POSITION IT WOULD RETURN TO LOCKED. PERFORMED T-SHOOTING IAW SMM 24-03-50, NO CHANGE. SWAPPED #2 & #5 ACPDE'S, SWAPPED SWITCH MODULES & TESTED MICROWAVE CB'S, VERIFED ABLE TO UNLOCK & KEEP ON OB'S & VERIFED & PERFORMED OPS CHECK. SWAPPED ACPDE'S & SWITCHING MODULES BACK TO ORIG POSITIONS. TEMP INSTALLED ACPDE'S & BRACKET, REMOVED #5 ACPDE & INSTALLED SUPPLIED UNIT. OPS CHECKED GOOD, NO DEFECTS IAW SMM 24-52-52.