As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ICE PROTECTION TEST, PNEUMATIC IN THE AIR, THE EICAS CAUTION MESSAGE FOR NR 1 A/C PACK VALVE FAIL. MESSAGE WENT AWAY WHEN TEXT ENDED. ADJUSTED & TORQUED NR 1 PACK UPPER CLAMP IAW EM-21-056. PERFORMED OPS CHECK OF ANTI ICE SYSTEM, FOUND GOOD. PERFORMED OPS CHECK OF NR 1 PACK SYSTEM FOUND GOOD IAW AMM 30-00-00 & AMM 21-51-00.