LTT HAS GEAR INDICATORS NOT ILLUMINATED; THEN SHOWED NO GEAR UP INDICATION.

Narrative

ON THE GND IN CMH; DURING THE BEFORE START CHKLIST; IT WAS NOTICED THAT THE 'A' GEAR INDICATION SYS LIGHTS WERE NOT ILLUMINATED. THE 'A' SYS CIRCUIT BREAKER HAD POPPED. IT WAS RESET; THE CAPT CHKED THE GEAR INDICATOR LIGHTS; THEY WORKED PROPERLY. A SHORT TIME LATER THE 'A' LNDG GEAR SYS CIRCUIT BREAKER POPPED AGAIN. THE CAPT DID A WALKAROUND; AND WE DISCUSSED THE WET SAND ON THE GEAR AREA. HE CONTINUED TO WORK ON THE SIT WHILE I DID THE LOAD MANIFEST AND GOT THE CLRNC. WE TAXIED TO RWY 28R AND TOOK OFF. I WAS THE PF; THE CAPT WAS THE PNF. UPON GEAR RETRACTION THE GEAR INDICATOR DID NOT SHOW A POSITIVE UP INDICATION. THE GEAR WAS CYCLED UP THEN DOWN AGAIN; THE SAME THING HAPPENED. DURING THE CYCLING OF THE GEAR THE 'A' GEAR INDICATOR DID NOT SHOW A POSITIVE GREEN INDICATION. I STATED MY CONCERN TO THE CAPT AND SUGGESTED THAT WE RETURN TO CMH. HE NOTED THAT; BUT ELECTED TO CONTINUE ON AND TROUBLESHOOT THE PROB. HE NOTIFIED ATC OF THE PROB. HE CONTACTED MAINT AND RAN THE APPROPRIATE CHKLISTS. HE CONTACTED EXCEPTIONS AND BRIEFED THE FLT ATTENDANTS AND THE PAX. I FLEW THE ACFT AND MONITORED COM #1. AS A PRECAUTION; THE CFR TRUCKS WERE ROLLED AND WE LANDED WITHOUT INCIDENT AND TAXIED TO THE GATE.