MD-83
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe
Flight Crew Overcame Equipment Problem; General Declared Emergency
Aircraft
Upon lowering the landing gear on approach the left main gear indicator light (green) was blank. Nose and right main indicating green. I assumed it was a bulb failure but did a go-around to be safe and before raising the gear asked the Tower for a look/see and they said all appeared normal. We thought cycling the gear might also resolve the problem so the landing gear was raised after passing the Tower. VFR/CAVU weather.   While I was trying to find spare bulbs and the First Officer was flying; he tested the annunciator lights and noticed that now that none of the landing gear green or red lights would come on. Regardless I replaced two of the four left main light bulbs. On down wind we lowered the landing gear early to see what indications we would get. All the physical; audible; and nose gear extended indications were completely normal; however now the entire gear annunciator panel was blank/inop. I then found the 'Landing Gear Warning' P26 circuit breaker popped. I attempted to reset it but it would not.  Knowing there is no specific emergency procedure for this; we declared an emergency; and proceeded with a normal landing. I felt 99% sure this was an annunciator problem and not a landing gear problem. The landing was normal except for continuous aural warnings. We pulled the CAWS circuit breaker after landing to stop the aural warnings. The emergency crews indicated every thing looked normal so we taxied to the gate.   Maintenance did subsequently find an electrical problem with the gear annunciator panel.
MD-83 Captain reported problems with the landing gear indicating system that developed into a complete failure. Crew was confident the gear was down so they declared an emergency and made a normal landing.