What was found
UPON EXTENDING GEAR, NOSE GEAR DOWN LIGHTS DID NOT ILLUMINATE, OTHER SWITCHING STUCK IN AIR MODE. NOTE: NO NOSE UNSAFE LIGHT ILLUMINATED, AFTER LANDING TAPPED ON NOSE GEAR DOWNLOCK SWITCH LIGHTS CAME ON. REMOVED AND REPLACED SWITCH AS PER DC9 MM CH 32-60-00 PG 1 PARA 1 GENERAL C 1 THRU 5 ITEM PARA 2A AND B1 AND 2. P/N 700-001-01-01, S/N OFF 9676, S/N ON 10841.