As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE LEFT DUCT PRESSURE 10 PSI THE BLEED DISCRET LIGHT ON OVERHEAD PANEL CAME ON FOR SEVERAL SECONDS. REF LOG PAGE 0965172 ITEM 3. T/S BLEED SYSTEM AND FOUND LOOSE B NUT ON PRV SUPPLY PRESSURE LINE, TIGHTEN B NUT OPS CK WITH ENGINE RUNNING GOOD IAW FIM 36-10 FT 838 AND AMM 36-11-00.