What was found
AFTER LANDING & APU START, AMBER ECU OVERHEAT MWP LIGHT ILLUMINATED. NOT GETTING ANY AIR FROM APU AT TIME. NOTICED THE ECU OVERHEAT LIGHT, CREW NOTICED A BURNING ODOR IN COCKPIT & GALLEY AREA. AFTER SECURING ACFT & OPENING FORWARD SERVICE COMPARTMENT DOOR, NOTICED A STRONG ELECTRICAL BURNING ODOR FROM THE FSC. WITH POWER REMOVED FROM ACFT & FSC DOOR OPEN, ODOR HAS SINCE DIMINISHED NO CIRCUIT BREAKERS APPEARED TO BE TRIPPED. TROUBLESHOT SYS TO BAD COMPRESSOR OUTLET OVERHEAT SENSOR & JET DUMP VALVE. REPLACED BOTH UNITS IAW MM TASK 21-52-45-900-801 & TASK 21-52-11-900-801. OPS & LEAK CHECKED GOOD.