As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB OUT NR 4 BLEED AIR SHUTOFF VALVE CLOSED CONFIRMING NO BLEED FROM ENGINE. THE CREW CYCLED SWITCH SEVERAL TIMES AND MOVED THROTTLE WITH NO HELP. ON DESCENT NR 4 BLEED AIR SHUTOFF VALVE OPENED. THEY LANDED AT DEPARTURE WITHOUT FURTHER INCIDENT. MX INSPECTED AND CLEANED CONNECTOR PLUG TO BLEED AIR SHUTOFF VALVE. OPS CHECK GOOD IAW MMK 36-12-9. ACFT WAS RETURNED TO SERVICE.