As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING AFTER START CHECKLIST RECALL MASTER CAUTION SHOWED AIR COND & CONT CABIN ZONE TEMP FOLLOWED QRH & MEL PROCEDURE LITE EXTINGUISHES WITH MASTER CAUTION RESET. GROUNDED - YES. PERFORMED BITE OF BOTH ZONE TEMP CONTROLLERS REF B737-800 FIM 21-62 TASK 801. NO FAULTS FOUND ON EITHER ZONE TEMP CONTROLLER. MEL 21-21G CLEARED.