As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU PNEUMATICS DROP ALL CYCLE BETWEEN 15-20 PSI DURING LEFT ENGINE START.AIRCRAFT BACK TO BLOCK AND GROUNDED BY MAINTENANCE. MAINTENANCE DEFERRED THE APU PER MEL 49-11-1A. PLACARD INSTALLED; AIRCRAFT REMAINS NON ETOPS.AIRCRAFT RETURNED TO SERVICE