As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LANDED UNDER AMBER ALERT DUE TO NR 1 ENGINE AT FLIGHT IDLE DUE TO COMPRESSOR STALL AND HIGH EXHAUST GAS TEMPERATURE. EMERGENCY EQUIPMENT CALLED AS PRECAUTION. TROUBLESHOOTING IDENTIFIED FAILED 8TH STAGE PNEUMATIC CHECK VALVE. AFTER EXTENSIVE TROUBLESHOOTING, IDENTIFIED CAUSE AS 8TH STAGE PNEUMATIC CHECK VALVE. REPLACED VALVE & CORRECTED RESULTANT DAMAGE. VALVE FAILED RELEASING THE POPPET SHAFT.