As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LOUD NOISE FROM E/E COMPARTMENT UNDER 1L F/A SEAT. FOUND NOSE LANDING GEAR STEERING METERING VALVE BYPASSING IN FULL RT TURN POSITION. DEPRESSURIZED CTR HYD SYSTEM AND RE-PRESSURIZED. EXERCISED NOSE GEAR STEERING SEVERAL TIMES AND NOISE WENT AWAY. NOSE GEAR STEERING OPERATION NORMAL PER AMM 32-51-00. ETOPS CATEGORY 'F': ANY OTHER EVENT DETRIMENTAL TO ETOPS.