What was found
ON FAE, FLT 202 - MDSD-KMIA - UPON CLIMB-OUT, CABIN ALTITUDE FOLLOWED AIRCRAFT RATE OF CLIMB, ALL DOOR LIGHTS OUT, OUTFLOW VALVE CLOSED, LEFT DUCT PRESSURE INDICATED 70 PSI, RIGHT DUCT PRESSURE INDIATED 30 PSI. AIRCRAFT AIR RETURNED TO MDSD. ON GROUND MAINTENANCE, RESET THE PACKS AND THE AIRCRAFT PRESSURIZED IAW MM 21-00, 21-11-0 AND 21-31-0. ALL SYSTEMS WORKED NORMAL IN AUTO AND MANUAL MODES. AIRCRAFT WAS RETURNED TO SERVICE. (M)