Last fall (around mid-October), I installed two LED tube lights in a fluorescent fixture--since there were three lights total, it had two LEDs and one fluorescent bulb. A few days ago, I started running into an issue where all three lights in the fixture (not just the LEDs) would suddenly turn off and not turn back on for several hours. I've tried switching around the bulbs and tried running it with just the two LEDs, but with no luck. When I have just the one fluorescent tube in the fixture, though, it works fine.

LED tubes are Philips UniversalFit; fluorescent tube is 32W/48 T8, and the fixture says "use only T8 32W MAX lamps." Ballast is Class P electronic. Based on a cursory Google search it appears that the LED bulbs may be causing the ballast to overheat and disconnect--but if this is the case, I'm not sure why it would take several months to appear.

I live in an apartment, going ballast-free isn't really an option; I'm limited to plug-and-play LEDs. Any suggestions or insights as to what may be going on would be most welcome!

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    Nice job on your first post! Including the brand/model of the bulbs & ballast is something few think to do on their first post. If you could edit to include info on the fixture itself, that would probably also be very helpful. While you're waiting for an answer, take the tour and read through the help center so you can learn how to make the most of the site.
    – FreeMan
    Jun 26, 2020 at 15:55
  • The mis match of wattages May have finished off the ballast, hopefully you have universal led tubes that can be direct wired, direct wire also saves power and you don’t have to worry about the ballast any longer.
    – Ed Beal
    Jun 26, 2020 at 21:52
  • Have you talked with your apartment's maintenance folks about the situation? They might be willing to entertain going to direct-fit if plug-and-play isn't playing nicely with your ballast... Jun 27, 2020 at 1:20
  • Thanks all! I'm still having issues with the fluorescent tubes only, so I think the ballast may be the issue. Let's see if they'll simply remove it and go for direct wire...
    – bscohen
    Jun 27, 2020 at 14:07

1 Answer 1


I agree; it sounds like a blown ballast to me. As Ed Beal suggests, if the ballast is rapid-start (2 wires per tube end) the imbalance of some LEDs some real fluorescent may have caused it undue stress. Or perhaps the ballast was starting to get marginal on its own, and using LEDs forestalled the problem until it deteriorated more.

I'd roll it back to real fluorescent and see if that takes care of it; if it does, happy dappy. Today's real fluorescents are superb in color quality, and electronic ballasts take care of the rest of the undesirable qualities of "That 70's Fluorescent". So no need to go LED if it works at that point.

Note that T8 real fluorescent tubes will not work on T12 ballasts or vice versa. They may "half-work" with bad side effects, and will stress out the ballast.

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