And more importantly, how can I fix it?

It is a large, 48 inch round hanging fixture. It looks like 8 pillar candles sitting on a wagon wheel. Each "candle" uses a 40watt candelabra bulb.

The other night, I changed the 3 bulbs that were burnt out -- I didn't think twice about it because they've been in the light for about 4 years. When I turned the fixture back on, SIX lights were out! The ones I changed and then some!

It might be my fault because instead of walking around the table, I turned the fixture to change the bulbs.

The light hangs on 18 inches of chain and woven through the chain is a thick cord. The cord goes through a canopy and there are 4 "rods" that go from the canopy to the round part of the fixture. The thick power cord goes through one of the rods and I'm assuming around the circle.

Should I take it down and take it to a lighting store? Call an electrician? Is it an easy DIY?

Now that I think about it.. could dust have built-up and something shorted out when I changed the bulb? or something?...