As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING AN OPS CHECK OF THE FAN AIR VALVE FOUND BLEED LEAK ON THE NR 1 ENGINE. TROUBLESHOOTING AND FOUND THE PNEUMATIC DUCT BETWEEN THE PRECOOLER AND PRSOV LOOSE AT THE FLANGE COUPLING ABOVE THE PRECOOLER. SECURED THE FLANGE COUPLING IAW IAW AMM 36-11-01. OPS AND LEAK CHECKED GOOD.