As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT ENGINE BLEED PRESSURE REGULATING SHUTOFF VALVE FAILED OPEN OR CLOSED OR LEFT AIR SUPPLY & CABIN PRESSURE CONTROLLER FAILURE. REPLACED PRSOV CONTROLLER IAW MM. REACTIVATED PRSOV & ACCOMPLISHED OPERATIONAL TEST IAW MM. VALVE OPERATION NORMAL & NO EICAS MESSAGES. FOUND PRSOV HANGING CLOSED. REPLACED VALVE PER MM 36-11-09. ACCOMPLISHED RUN CHECK MM 36-10-00. NO MESSAGE, PRESSURE GOOD.