Each one was different. One had a little too much corrosion. A couple were in backwards. The last on had the bulb put in wrong, go figure....The interesting part was that as I fixed each light the others would stay bright. Once all of them were fixed I tried creating a problem on one socket to see if all the lights would give me the same symptoms and they didn't. The bad light would stay bright and the others would remain intact. Hope that helps...