As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WITH ISOLATION VALVE CLOSED AND NR 1 BLEED OFF LEFT DUCT PRESSURE DROPS TO 15 PSI THEN CLIMBS UP TO 19 PSI ETOPS FLT CHECKLIST 9A (8) A. ON GROUND WITH ENGINE NR 2 SHUT DOWN APU BLEED OFF L DUCT PRESSURE STARTS AT 0 AND CLIMBS TO 9 PSI. REPLACED NR 1 ENG PRSOV AND APU BLEED VALVE IAW B737NG AMM 36 11 04 400 801 AND AMM 49 52 11 400 801. LEAK AND OPS CHECKED GOOD.