As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNABLE TO CLOSE BLEED AIR WHEN THE NR 1 ENGINE IS THE AIR SOURCE. ACFT GROUNDED. VERIFIED THAT THE NR 1 ENGINE PRSOV IS CLOSED AND MOVES FREELY. VERIFIED THAT ELECTRICAL ON AND OFF COMMANDS AND GROUNDS CHECK OK. REF FIM 36-10-00-810-802 AND WIRING DIAGRAM 36-11-11. R & R THE NR 1 ENGINE BLEED AIR REGULATOR IAW AMM 36-11-03. LEAK AND OPS CHECKED GOOD.