As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WITH NR 2 ENGINE RUNNING DESELECTING BLEED SWITCH WOULD NOT TURN OFF PNEUMATIC SUPPLY (VALVE DID CLOSE WHEN ENGINE SHUTDOWN). INDICATIONS NORMAL. RAN NR 2 ENGINE APU BLEED OFF AND ISOLATED. HAD 15PSI DUCT PSI. HPSOV, PRSOV STILL OPEN, SWITCH OFF LIGHT OUT. SUSPECT CLOSE RELAY K10204. REPLACED RELAY AND PRSOV REGULATOR IAW MM, OPS CHECKED NORMAL.