What was found
AFT CABIN TEMP EICAS. PERFORMED BITE ZONE TEMP CONTROLLER, FOUND AFT TRIM AIR VALVE FAULT, DEFERRED AFT TRIM AIR VALVE PER MEL 2161BB, VALVE SHOWED CLOSED ON EICAS, SECURED CLOSE PER CB'S PULL OUT IAW MEL PROCEDURE 1. REPLACED AFT TRIM AIR VALVE, NO HELP. SUSPECT BAD VALVE FROM STOCK. CONNECTOR WAS DIFFICULT TO REMOVE AND INSTALL. RECOLLARED BREAKERS. REPLACED TRIM AIR MODULATING VALVE PER MM.