As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FLT LEVEL 370, HEARD A LOUD BANG AND NOTICED THE NR 2 ENGINE STALLED & N1 DECREASED TO 30%. DESCENDED TO FL 310 & RAN QRH FOR ENGINE COMPRESSOR STALL & WAS ABLE TO REGAIN NORMAL ENGINE OPERATION FOR APPROXIMATELY 5 MINUTES, WHEN THE NR 2 ROLLED BACK AGAIN TO 30% N1. SECURED THE ENGINE IAW QRH. DECLARED AN EMERGENCY & DIVERTED. R & R THE NR 2 ENGINE.