What was found
CABIN ALTITUDE WARNING HORN SOUNDS AT CRUISE (FL330) CABIN ALT WAS 11 500FT. STANDBY MODE ARRESTED CLIMB AND REDUCED CABIN ALT TO JUST BELOW 10 000FT. PERFORMED DECAY CK REF AMM TASK 21 00 05 782 001, OPS CHECK GOOD. REMOVED A/C POWER REF AMM 24 22 00 862 011, REMOVED & REPLACED PRESSURE CONTROLLER REF AMM 21 31 21, OPS CHECK GOOD. REMOVED & REPLACED FOR PRECAUTION. SUPPLIED A/C POWER REF AMM 24 22 00 862 001, A/C OK FOR SERVICE.