As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE ALTITUDE, THE NR 2 ENGINE WAS UNRESPONSIVE TO THRUST LEVERS AND AUTO THRUST LEVERS. THE NR 2 ENGINE FROZE AT 95% N1. THE CREW SHUTDOWN THE ENGINE AND SECURED AT FL 150. MAINTENANCE REMOVED AND REPLACED THE NR 2 HMU ASSEMBLY AND OPS CHECKED GOOD IAW AMM 73-21-10, PAGE 401, AIRCRAFT RETURNED TO SERVICE.