What was found
ON APPROACH, AFTER GEAR WAS EXTENDED, NO GEAR DOWN INDICATION WAS NOTED ON ANY OF THE (3) ANNUNCIATORS. ABORTED APPROACH INITIATED A GO-AROUND AND RAN THE GEAR CHECKLIST. TOWER ADVISED ALL GEAR APPEARED TO BE DOWN. BLEW GEAR DOWN AND REQUESTED EMERGENCY EQUIPMENT TO BE STANDING BY. ATC DECLARED EMERGENCY AND AIRCRAFT LANDED WITHOUT INCIDENT. AIRCRAFT IN MAINTENANCE AT THIS TIME. ON SITE MAINTENANCE PERFORMED GEAR RETRACTION TESTS, SERVICE BLOWDOWN BOTTLE, ALL CHECKS GOOD. CREW PERFORMED OPERATIONAL CHECK FLIGHT WITH NO DEFECTS NOTED. AIRCRAFT RETURNED TO SERVICE 5-26-07.