I put in two 2x2 drop in fixtures in a basement drop ceiling on a new grounded circuit, they work fine. The customer call me back to replace two russels with two 2x2 drop in fixtures in a new drop ceiling on an existing non-grounded circuit, they work fine, customer calls me that night, lights not working, go back ,ground lights, lights work fine. Customer calls me that night, lights not working. Now I feel like a dope, can't figure it out. Voltage is fine, tubes in, ballast good. I call a friend of mine and start to tell him the problem, before I can finish he tells me he knows what it is, but lets me finish. The "u" tubes with the metal brace cause this problem. I change the tubes with the plastic brace and the lights work fine. I check the ones that I put in first for the hell of it and they had the plastic brace. Amazing!
