Both my electrician and I are scratching our heads on this one. By changing out some off-brand LED bulbs in pre-existing fixtures, the inexplicable behavior was "cured." What is/was causing it? ...

Recently had the following work done:

  • new LED recessed lights installed in
    • (A) kitchen (updated old fluorescent fixtures to 6" cans, added some 4" cans),
    • (B) family room and living room (previously had no lighting in either);
    • dimmer switches for all of those;
  • some GFCI replacements;
  • wiring/installation of a ceiling mount fixture in each of two bedrooms.

Work was done in two phases:

  • rough-in (the wiring / housing for the lights and switches)
  • final (installation of the lights, switches, and plugs).

There were NO problems with existing lights prior to any of the work, nor after the rough-in, prior to the final.

FWIW, this is a small tract house, 40 years old.

After the final work, when we attempted to turn on any of a certain 4 previously-existing lights, under a given sequence of turning on new lights, the existing 4 were extremely dim, to the point where they almost looked off. All 4 problematic lights are on the same circuit with each other, and all 4 used an off-brand LED bulb ("Bulbstar"). None of the 4 are on dimmers.

Sequence to trigger problem:

  1. Turn on new 6" kitchen lights then any of the above 4 problematic ones. Kitchen lights are on a different circuit than the 4. Or:
  2. Turn on either of the two new bedroom lights, then any of the above 4. These are all on the same circuit with each other.

Problem does NOT occur in any of these cases:

  1. Turn on any or all of the 4 problematic lights before turning on the kitchen's new 6" cans or either bedroom's new lights.
  2. In the 4 lights, replace the "Bulbstar" bulbs with either a CFL, incandescent, or another brand LED (e.g. FEIT). Individually replaced and tested each of these 4 separately.
  3. No problems linked to turning on new kitchen 4" cans, lights in family room or living room.


Is this purely a defect / incompatibility in the Bulbstar bulbs? Or is it something more serious in the house wiring?

  • 1
    I never heard of Bulbstar but if it solved your problem, jump for joy. I have seen many, many instances where cheap, no name bulbs and dimmers have caused very similar problems. When in doubt, replace a LED bulb with an incandescent to see if the problem still exists. LED bulbs are sensitive to voltage fluctuations and cheap ones are even more sensitive.
    – JACK
    Sep 2, 2021 at 11:44
  • @JACK I think the OP is wondering if the Bulbstar bulbs are the problem, not indicating that they're the cure...
    – FreeMan
    Sep 2, 2021 at 14:06
  • TBH, if replacing the Bulbstar bulbs with some other brand solves the problems in all light-on/light-off sequences, I'd say it's the bulbs, not the wiring. Chuck the cheapo bulbs and go with quality. I bought 2 boxes of cheapo LEDs a while back and they burnt out faster than incandescents did (some died in as little as 6 months). I've been replacing them with more expensive, brand name bulbs as they go (now that I've burned through them all) and not having any LED failures.
    – FreeMan
    Sep 2, 2021 at 14:09
  • @FreeMan The "it" I was referring to was the second sentence in the first paragraph....... :-)
    – JACK
    Sep 2, 2021 at 15:01
  • To me it sounds like a poor connection someplace. An inspection is just someone looking at the wiring and devices and verifying they meet code requirements so don’t think that an inspector would catch something like that. If the circuit has both lighting and receptacles a backstab connection is usually where I find problems like these and they can come and go. I mention backstabs the push in connections but it can happen with wire nuts also rare but it happens. Testing the circuit with a heavy load like a toaster/ hair dryer can cause it to open and then troubleshoot for is easier.
    – Ed Beal
    Sep 2, 2021 at 16:15

1 Answer 1


Cheap Chinese junk is cheap junk.

That said, it certainly could be a harbinger of something wackadoodle out of left field, like a lost neutral. That's a slippery one with really weird symptoms; I found out about our lost neutral when my sweetie said "the toaster is slow today".

The startup surge (inrush) of the other bulbs may be causing a voltage dip or otherwise bothering the cheapo's.

For a lost neutral, you can check all your receptacles for voltage changes as you turn on/off a big load like a hair dryer or toaster.

But for problems generally, if the fixtures permit incandescents, I would change to incandescents as they are good at illustrating power problems that LEDs will conceal.

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