The florescent bulbs burned out in the light fixture in my wife's closet. I tried turning them around in their mounts and one of them had a faint glow but nothing else. I had purchased some 48" T8 replacements but they were LEDs. So I replace the originals with the LEDs and they worked fine at first. Now, when I flip the switch they come on for a few seconds and then go dark. If I toggle the switch they will sometimes very briefly flicker but still remain dark. I purchased a new switch because it seem to me that was the problem at first but before i go to the trouble of replacing it I thought I would see if there may be another possibility. Any ideas?