I replaced the old fluorescent tube bulbs with Phillips led tube lights a couple of years ago and have had problems ever since. The bulbs would turn off when they warmed up and turn back on when they cooled down. Now the led tube bulbs won’t turn on at all. These bulbs use the ballast but I think I might need to change to a different ballast. The bulbs I have are replacements for T8 or T12 fluorescents 4 ft. 32 to 40 watt and will work with either 1 in. or 1.75 in.. The led bulbs are 16 watt. I need to know if anyone else has had this pr

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    I have always had good luck with the ballast-bypass bulbs. The only time I tried using ballasted LEDs like yours, was with a fixture where the ballast was annoyingly baked into the molded plastic end caps of the fixture, so I couldn't bypass it. I bought LED bulbs that were not ballast bypass. They did not work! I threw out the fixture. So there's a data point for you.
    – jay613
    Commented Dec 7, 2023 at 2:32
  • If you have (and are keeping) ballasted LEDs you need a functional ballast as well as a functional LED tube. At this point it's likely hard to tell if only one of the two has failed or if both have, unless you have a working ballasted fixture you can test all the tubes in, or you go out and buy two or four good florescent tubes to test all the ballasts. IMHO, ballasted LED tube replacements are strictly for people who won't open the fixture to do some trivial re-wiring to use direct wire LED replacements, or replace a bad ballast with a good ballast and keep using florescent tubes.
    – Ecnerwal
    Commented Dec 7, 2023 at 3:12
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    If they came from Philips with one l a couple of years ago the bulbs should have something like 5 years of warranty left, and a company that exists to stand behind it. Phillips with two ls you might not be so lucky.
    – Ecnerwal
    Commented Dec 7, 2023 at 3:49
  • Just buy full LED replacement lamps. It's not worth retro fitting old ones. Commented Dec 8, 2023 at 6:05

1 Answer 1


There are 4 types of common LED tube:

  • LED direct wire / ballast bypass, single-ended (Type B)
  • LED direct wire / ballast-bypass, double-ended (Type B)
  • LED plug-n-play / ballast required (Type A)
  • Universal, the previous two at once (Type A+B)

It sounds like you have the 3rd or 4th kind.

If you insist on using plug-n-play LEDs, you must maintain the fluorescent ballast. It sounds like yours has gone out on you.

You'll need to either replace the ballast, or, decide to switch to a "ballast bypass" LED - and here, we recommend the double-ended ones. The wiring is simpler and you never have to worry about a time-wasting stupidity called "shunted tombstones". If your LED is "universal" type, you already have this.

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