As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 PACK LIGHT ILLUMINATED ON DESCENT. QRH PROCEDURE ACCOMPLISHED. LIGHT WENT OUT WITH "RESET" AND REMAINED OFF FOR DURATION OF FLIGHT. ACFT GROUNDED. PERFORMED BITE CHECK AT LT CONTROLLER. FOUND FAULT NR ZONE TRIM AIR VALVE, REPLACED VALVE IAW 21-61-21 AMM. BITE CK AT LT AND FAULT CLEARED. OPS CKD, APU OKD, NO LEAKS.