As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE 1 ROLLED BACK AT FL 370 IN CLEAR AIR AUTO IGNITION AND RE-LIGHT OCCURRED / PERFORMED TROUBLESHOOTING OF #1 ENGINE ROLLBACK IAW TSM 72-00-00-810-806-A. HMU FOUND BAD, REMOVED AND REPLACED PER IAW AMM 73-21-10-400-002, OPS AND LEAK CHECKS GOOD.