I've got a 36" T5 fixture with 4 bulbs made by ATI. I recently changed all 4 bulbs and now I have a problem. Two of the bulbs will not start. Well, sometimes they will if you take a bulb out and reinsert it, but the pair will stay lit for only 30 sec or so. A year ago when I last changed bulbs, the same pair were a little touchy at first, but then after a couple days were OK and didn't have a problem until the latest bulb change.
Since there had been some minor issues with the bulbs starting during the first week after the previous bulb change, I assumed that the problem was with the ballast. I replaced the ballast with an ATI ballast and also changed the bulb holders (non-shunted since I had read that ATI used programmed start ballasts) since one was broken. Now, the pair will intermittently light for that 30 sec period then go off. I even tried reinstalling the old bulbs, and combinations of both old bulbs and old/new bulbs. Most often the pair will not start at all. So, new ballast (interestingly enough, the old ballast did not have the metal cover on it, but the new one could be snugly placed in the fixture, but everything looked the same with the old/new ballasts as far as I could tel) did help, new bulb holders didn't help. Also, replacing a broken ventilation fan didn't affect things either.
Any suggestions would be greatly appreciated. Thank you.
Since there had been some minor issues with the bulbs starting during the first week after the previous bulb change, I assumed that the problem was with the ballast. I replaced the ballast with an ATI ballast and also changed the bulb holders (non-shunted since I had read that ATI used programmed start ballasts) since one was broken. Now, the pair will intermittently light for that 30 sec period then go off. I even tried reinstalling the old bulbs, and combinations of both old bulbs and old/new bulbs. Most often the pair will not start at all. So, new ballast (interestingly enough, the old ballast did not have the metal cover on it, but the new one could be snugly placed in the fixture, but everything looked the same with the old/new ballasts as far as I could tel) did help, new bulb holders didn't help. Also, replacing a broken ventilation fan didn't affect things either.
Any suggestions would be greatly appreciated. Thank you.