What was found
ON FINAL NLG BOTH SYSTEMS SHOWED UNSAFE, GO AROUND TO HOLDING TO USE GRAVITY EXTEND PROCEDURES. THREE GREEN SAFE LIGHTS AFTER PROCEDURE WITH NORMAL LANDING, AND TOW IN CREW STATED GOT 3 UNLOCK (AMBER) RED LIGHT AND 2 GREEN LOCK LIGHTS ON MLG`S ON BOTH SYSTEMS BEFORE INITIATING GO-AROUND ADDED MPN A25421001-2, CPN 3211274 QTY 1 UPLOCK MSN 1114661. T/S PER TSM 32-30-00 PG112 FIG 117, AND DETERMINED THAT NLG UPLOCK ASSY NEEDS TO BE REPLACED. R & R NLG UPLOCK ASSY IAW AMM 32-31-21-4, & CYCLED NOSE GEAR 8 TIMES WITH NO FAULTS OR LEAKS DURING RETRACTION OR EXTENSION OF NLG INTERROGATED PROX BOX AS A PRECAUTION, BUT NO FAULTS FOUND. ACFT OKAY FOR SERVICE.