What was found
FLIGHT 3537. DURING DESCENT, CABIN PRESSURE CONTROLLER MALFUNCTIONED. CABIN PRESSURE STARTED TO CLIMB TO 9000 FT WHILE DESCENDING FROM FL360. DECLARED AN EMERGENCY AND CONTINUED BELOW 10000 FT. CABIN OXYGEN MASK DID NOT DEPLOY AND AIRCRAFT LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. PERFORMED OPS CHECK OF MANUAL MODE IAW MM 21-31-00 OP'S CHECKED GOOD, REMOVED AND REPLACED DIGITAL CONTROLLER IAW AMM 21-31-01 OPS CHECKED GOOD. AIRCRAFT RETURNED TO SERVICE.