As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT ENGINE BLEED OFF EICAS, NO AIR AVAILABLE WHEN ENGINE UP AND CYCLED S11 BREAKER. ACCOMPLISHED HEALTH CHECK IAW 36-00-99. FOUND PRSOV FILTER MORE THAN 90% CLOGGED. FOUND PRV SHAFT WORN OUT AND PRV CONTROLLER OUTSIDE OF HEALTH CHECK PARAMETERS. REPLACED SHUTOFF VALVE.