New dimmer borks LED sockets

Old 06-23-21, 12:11 PM
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New dimmer borks LED sockets

A few years ago I replaced four 50w halogen (MR16 GU5.3) with equivalent LED bulbs.
I may or may not have also replaced the dimmer at that time.
I don't remember.
Everything worked fine, essentially, since then.
The lowest dimmer setting was a bit high still for my tastes, but other than that it was fine.
Then, a few days ago, I turned on the switch and there was flash, which I thought was the beginnings of a power failure.
The AC in the rest of the house remained operational.
But all of the 4 led bulbs stopped working.
Some sort of power surge, I'm guessing.

I assumed that the dimmer itself had blown and that changing it might help, and I ordered a new one.
It's a Leviton Decora model that is be capable of working in either a 1-way or 3-way switching system and had correct looking (to me anyway) specs.
(This circuit is just 1-way. One dimmer/switch for all 4 bulbs.)

After I connected the new dimmer, there were only 3 of the 4 bulbs lighting up.
Also, the lights were flickering pretty badly until I did a final setting on the dimmer (first time I'd ever seen a need for a setting like that) for maximum dimmer level.
After that, the flickering settled down.
But a minute or two later, another bulb stopped working, again after a flash.

At first I thought the bulbs had just blown, even though they were only a year or 2 old, which isn't supposed to happen with LED bulbs.
But further tinkering revealed that all 4 bulbs were still operational.
It was the 2 base sockets themselves that had stopped working.
Now, when I was using halogen bulbs in this room, I used to burn out the base sockets all the time.
That's the main reason I switched to LED bulbs.
So, I have replaced a few of these base sockets myself in the past.
And I happened to have a few spares around the house today.
After changing out one of the suspect base sockets, the issue persists.

So, something must have burnt out further down the circuit, possibly somewhere in the wall as far as I know?
Actually, I don't know.
And that's why I'm asking you all here.
Originally, I thought these lighting circuits must have a transformer hidden somewhere, presumably in the attic.
And my attic is pretty inaccessible where these pot lights are located, so I can't even look into that.
But that just doesn't seem right anyway.
I figure now that the AC to DC conversion must be occurring inside the dimmer itself.

I'm holding off on calling an electrician because my full immunity has not yet kicked in after my vaccinations and I don't want any strangers in the house yet.
So I'm trying to troubleshoot it myself still in the meantime.
Any tips/thoughts?

Is it possible that the new dimmer is just faulty and needs to be replaced again?
That seems like a long shot based on the symptoms.
E.g. Why would only 2 sockets fail?
Also, the 2 bulbs that still do work are unaffected now by the setting of the dimmer slider.
Again, any thoughts appreciated.

Joey in Toronto.

Old 06-23-21, 12:22 PM
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Welcome to the forums from far away.

Borks ?!!?!?

When you suspect a dimmer issue..... don't replace it..... bypass it first to make sure it is bad.
Put a switch in its place and eliminate the dimmer as the problem.
Old 06-23-21, 12:36 PM
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Inside my switch box there are 2 black wires and 2 white wires.
The white wires are all connected to each other with those twisty things.
That's the way it was when I bought the house.
I've determined that one of the black wires is the hot and the other is the ground.
Why they used black for both is a mystery.
I've never touched the white wires and have no idea what they do. lol
But I've changed this dimmer a few times now and I'm pretty sure I know which of the 2 black wires is the hot.
So, based on your idea above...
If I simply attached both black wires together, the circuit should be completed.
But w/o the dimmer in the circuit, won't I be sending 110 volts of AC to my light fixtures instead of the 12 volts DC that they operate on?
Isn't that dangerous?
Old 06-23-21, 01:15 PM
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Your bulbs/fixtures should be setup for the voltage they operate on.
A dimmer is not used to lower operating voltage.

The two white wires tied together are the neutrals.
There should be two black wires ...... one hot and one load to the lights.
Most dimmers don't care which is which.
joegold voted this post useful.

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