What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS DURING CRUISE, LIGHTS TEST SHOWED NO GREEN INDICATION FOR LEFT MLG ON FWD INST PANEL OR ON AFT OVHD. SOME LIGHTS WOULD NOT PRESS TO TEST. WHEN GEAR LOWERED FOR LANDING HAD NORMAL 3 GREEN INDICATIONS ON FWD INST PANEL AND AFT OVHD. AN EMERGENCY WAS DECLARED. GEAR PINNED ON RUNWAY AS PRECAUTION. MAINTENANCE REPLACED OVERHEAD LEFT LANDING GEAR LIGHT ASSEMBLY AND LANDING GEAR LIGHT PLATE BASEPLATE ASSEMBLY AND OPS CHECKED GOOD IAW AMM 33-18-00.