LED light strips going off and on

Question

I have two Sonneman LED light strips in my bathroom, each connected to its own transformer. They're controlled by a single dimmer. They have worked fine for 4 years but now when I switch them on they go off and on, off and on, and so on, continuously and simultaneously. Does this suggest a dimmer problem given that it's not one light doing this, but both, simultaneously? Also why would a dimmer go bad after 4 years?

I'll just add that - before this started happening - when the dimmer was turned all the way up, the lights blinkered, so we kept them turned down a notch.

Answer 1

The power supply is "crowbar"-ing

The load of the LEDs is overloading the DC power supply. It powers up, detects overcorrect, and shuts off to protect itself. Remove the overload.

Before, that was only a problem when the LEDs were at max brightness per the dimmer. You didn't fix it then, and chose to "work around it". That unresolved problem has come home to roost, as aging components in the dimmer cause it to be brighter or to be stuck "on" full.

What does this mean? Power supply is too small

You need a bigger (more amps) DC power supply.

Once that is taken care of, you may find a second problem, such as a dimmer that is stuck on full, as I alluded. If you don't really care about dimming, you don't need to dim.

Answer 2

I think you have a leading edge dimmer and you need a trailing edge dimmer. I suspect this because you have had the problem from the start, just not as pronounced. This can happen when the dimmer is not the correct type. You can purchase them either way or some do both. Replace the dimmer. I find it highly unusual that both "transformers" DC power supplies would fail exactly the same way and in the same time frame. Since I do not have the dimmer information get one that does both ways and try it, if it gives you problems simply set it the other way.