As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLIMBING OUT AT 8000 FT, THE LT PACK LIGHT CAME ON. QRH PROCEDURE RESET AND CAME ON 1 MINUTE LATER. AIR RETURN TO DEPARTURE. USED APU WITH LT PACK OPERATING NORMAL. FOUND LT ZONE TEMP/PACK CONTROLLER FAULTY. R & R LT CONTROLLER REF AMM 21-61-20-000-801/400-801. OPS CHECKED GOOD. ROTABLE PARTS CHANGE WAS INDICATED - TT 1497114, SN OFF 01701 CONTROLLER, CAB OFF 58-2161-9-0002 1701, ON 58-2161-9-0002 3807.