As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RIGHT PACK ILLUMINATION ON RECALL- MASTER CAUTION RESET. RELEASED PER MEL #21-32B RIGHT PACK PRIMARY TEMPERATURE CONTROL INOP. GROUNDED - YES. REFERENCE ABOVE. DEFERRAL WRITTEN IN DEFECT DESCRIPTION BLOCK. FOUND CONT CAB ZONE TEMP AND FWD CAB ZONE TEMP ALSO ILLUMINATED ON RECALL. ON PZTC #2 FOUND CONTROLLER FAULTING ITSELF. REMOVED AND REPLACED RH PZTC REF B737-800 AMM 21-61-20. OPS TEST PASS. OPERATED RH PACK FOR APPROX 10 MINUTES. NO FAULTS NOTED.