What was found
CONTROL CABIN ZONE TEMP LIGHT ILLUMINATED. LIGHT RESETS WITH MASTER CAUTION RESET. COMPLIED WITH QRH PROCEDURE, NO CHANGE. LIGHT ILLUMINATES ON RECALL. ACFT GROUNDED. ACCOMPLISHED BITE OF PTC, REF FIM 21-62, TASK 801, FAULTED ON NR 2 PTC FLIGHT DECK TRIM VALVE. WAS ABLE TO CLEAR FAULT WITH NO FURTHER FAULTS, RAN PACK AND RE-ACCOMPLISHED BITE, NO FAULTS. VERIFIED FLIGHT DECK TRIM VALVE CYCLES.