What was found
STL - FLT 491 - AFTER TAKEOFF UPON GEAR RETRACTION HAD NOSE GEAR UNSAFE INDICATION. RECYCLED GEAR, NO HELP. RAN ABNORMAL PROCEDURES, INDICATION REMAINED. REPLACED NOSE LANDING GEAR UPLOCK SWITCH. PIN WAS STUCK IN GROUND POSITION, PERFORMED REMOVAL/INSTALLATION AND ADJ AND TEST PER MM 32-61-71 PG 402-502, OPS CHECK GOOD.