As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON SPEED REDUCTION AT FL37 LOUD BANG HEARD WITH MOMENTARY AIRCRAFT SHUDDER. FLT ATTN IN MID GALLEY AREA REPORTED SOUND AND CREW REPORTED NO ABNORMAL ENG INDICATIONS. FADEC DUMP INDICATED SURGE ON NR 2 ENG. REPLACED NR 2 ENGINE, OPS CHECK GOOD.