Light behavior (now I'm really confused)
Last night I purchased the closest T8 I could find along the drive home, a F17T8 soft white. Put the tube in and switched the light on, and the tube lit at what seemed full brightness. Let it run for a bit and didn't notice any undue heating of the tube or the lamp, so I put the plastic diffuser cover back onto the lamp.
After a few seconds, the tube flickered badly a few times and then dropped out of operation. The lamp, which normally makes a little humming/growling noise on startup and then is fairly quiet, switched back to the louder noise level, and the ends of the tube were glowing pinkish, almost like it was trying to preheat or something.
Switched it off, took the cover off, and repeated the experiment. It is repeatable ... Tube will start and seem happy with cover off, and then drop out of operation when the plastic cover goes on. Can anyone fill me in on whats going on? I'm beginning to wonder if whatever serves as the ballast/electronics on this lamp are failing or something.