As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
L ENG BLEED WON'T COME ON. LT ENG BLEED CONTROL AND IND BREAKERS PULLED IAW MM. ALSO CONNECTOR PLUG AND BONDING WIRE REMOVED ON OTBD SIDE OF PRSOV IN PYLON. PRSOV IS LOCKED CLOSED. REPLACED AIR SUPPLY PRESSURE REGULATING SHUTOFF VALVE. RAN ENGINE NR 1 AT IDLE CYCLED ENGINE BLEED SWITCH BLEED ON LIGHT OFF, BLEED OFF LIGHT ON. OPERATES NORMALLY.