What was found
FLIGHT DECK TEMP. CONTROL FAILED TO CONTROL DESIRED TEMP. IN AUTO OR MANUAL. ALSO NO TEMP. CONTROL WITH ANY SELECTOR. DURING APPROACH, NAV EQUIPMENT BEGAN ERONEOUS INDICATIONS, AUTO PILOT DISENGAGED, F/O'S DU-1 FAILED, THEN F/O'S DU-2 FAILED. F/O'S FMC FAILED, G/A FUNCTION ALSO FAILED. SUSPECT DUE TO UNCONTROLLABLE TEMP. CONTROL. REPLACED FLIGHT DECK ZONE DUCT OVERHEAT RELAY PER BLOCK 41. REPLACED TRIM AIR PRESSURE REGULATING VALVE IAW B767 AMM 21-61-06-4. OPS CHECKED GOOD. COMPLIED WITH B767 FIM 21-60-00.