As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MASTER CAUTION AIR CONDITIONING INDICATOR FLICKERS DURING A DUAL BLEED CONDITION AND WILL NOT RESET. ACFT GROUNDED. PERFORMED CABIN TEMP CONTROLLER BITE PROCEDURE IAW FIM TASK 21-61-801. NO FAULT NOTED, RECYCLED PACKS SWITCHES AND APU BLEED SWITCH ON P-5 OVERHEAD PANEL , NO FLICKERING NOTED MASTER CAUTION AIR CONDITIONING RESET.