As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTS AFTER ENG START, THE LEFT BLEED WOULD NOT CLOSE. SHUTDOWN NR 1 ENG, CYCLED LT BLEED CONTROL CB AND RESTARTED ENG, NO HELP. OPERATED ENGINE AND FOUND THAT LEFT PRSOV WOULD OPEN WITH SWITCH SELECTED TO OFF. REPLACED LEFT PRSOV. OPERATED ENGINE, PRSOV OPERATES OKAY.