As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON DEPARTURE OUT OF ATW WITH ONE PACK ON MEL THE OTHER PACK INDICATED OVERPRESSURE. THE CAPTAIN OPTED TO RETURN TO ATW. RECORDED LOGBOOK DISCREPANCY: WHEN TRANSFERRING BLEEDS, APU SELECTED RIGHT 10TH STAGE BLEEDS REMAINED CLOSED, RIGHT PACK HI PRESSURE C/W QRH CAS MIS COMP". MX REPLACED THE RH PACK PRESSURE REGULATING AND SHUTOFF VALVE.