What was found
PDX - AIR CONDITIONING CONTROL CIRCUIT BREAKER TRIPPED IN-FLIGHT AND COULD NOT RESET IN MANUAL. THE HOT AIR NECESSITATED SELECTING BOTH BLEED AIRS OFF, CABIN DEPRESSURIZED AND PERFORMED EVACUATION SMOKE PROCEDURES. AIRCRAFT LANDED WITHOUT FURTHER PROBLEMS. CABIN TEMP. CONTROLLER AND RIGHT HOT AIR MIXING VALVE REPLACED I/A/W MAINT. MANUAL. SYSTEM OPS CHECKED GOOD. AIRCRAFT RETURNED TO SERVICE.