As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEAR DISAGREE EICAS MESSAGE WHEN GEAR LOWERED ON APPROACH. ACCOMPANIED BY LDG GEAR MONITOR STATUS MESSAGE. QRH PROCEDURE RAN IN ENTIRETY FOUND LEFT SYSTEM RETURN CHECK VALVE P/N BACV10CD13 FOR THE NLG EXTENSION & RETRACTION BYPASSING. R&R BOTH LEFT SYSTEM RETURN CHECK VALVES FOR THE NLG EXTENSION & RETRACTION IAW AMM 20-11-00. PERFORMED NLG SWING PER AMM 32-34-00, OPS AND LEAK CHECK GOOD. REMOVED NLG JACK FROM A/C PER AMM 07-11-01.