As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PACK LIGHT ON MASTER CAUTION RECALL. GROUNDED - YES. FIM 21-53 TASK 821, BOTH PZTC'S HAVE NO PREVIOUS FLT FAULTS LOGGED. OPS CHECKED RIGHT PACK WITH NR 2 ENG BLEED, UNABLE TO DUPLICATE FAULT. VERIFIED RIGHT PACK OPS CHECKED NORMAL ON GND WITH ENGINE AND APU BLEED SOURCES. BOTH PTZC BITE VERIFY TEST NORMAL WITHOUT FAULTS.