As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER ENGINE START, LEFT ENGINE BLEED AIR INOP. MAINTENANCE IN WORK AIR SUPPLY BITE FAULTS PRSOV PRESS SENSE. REMOVED AND REPLACED PRSOV PRESS SEN PER M/M 451904 FOUND MUSCLE AIR LINE FITTING LOOSE REATTACH RAN ENG. OPS CKS OK PER M/M MFG 415G265-1.