What was found
LANDING GEAR WOULD NOT COME DOWN AFTER SELECTING GEAR LEVER DOWN. ALL RED A & B LIGHTS, EXCEPT LEFT MAIN A LIGHT, STAYED ON. LT MAIN GREEN A LIGHT WAS ALSO ILLUMINATED. ON THE GO-AROUND THE GEAR EXTENDED AND GOT NORMAL GREEN LIGHTS EXCEPT LEFT MAIN A LIGHT REMAINED OFF FOR ABOUT 10 SECONDS. UPDATE 11/5: ON APPROACH SELECTED GEAR DOWN WITH NO RESPONSE. GEAR DOORS REMAINED CLOSED. STARTED TO FOLLOW QRH PROCEDURE, ELECTRICAL OVERRIDE, WHEN GEAR FINALLY CAME DOWN. REMOVED AND REPLACED LANDING GEAR CONTROL BOX WITH SERVICEABLE UNIT. OPS CHECK GOOD. UPDATE: 11/5: REMOVED AND REPLACED SEQUENCE VALVE IN NOSE BAY. SYSTEM OPS CHECK GOOD AS PER EMB MM 32-30-00.