Kitchen counter LEDS are faulty- uniformly dim

[SUNRAY]

It's also a tell tale sign of a chromacity shift towards yellow, due to lower currents...

Thanks, that is what I have found when playing with COBs, especially when viewed out of the light beam.

But this

If the photo shows the true colour of the LED (yellowy slightly green light output), then the phosphor has degraded. Pretty common at that age and will need replacement.

is something I have not encountered or heard of before, which I readily accept as a schoolday.

 

[ericmark]

Years ago I played with red LED lamps, in University to try to make them brighter, the experiment was a failure, as the lux meter will clearly show the average light, which is not the same as the light perceived by the human eye. However the experiment was to over drive the LED but for a short time, and we found if over driven, the LED reduced output and stayed reduced.

My neighbour said the LEDs flickered a bit and went bright before going dim

So seems likely the driver went faulty, and damaged the LED's, so only cure is to renew them.

 

[SUNRAY]

Hi all,
... My neighbour said the LEDs flickered a bit and went bright before going dim, which suggested some sort of power surge but I find that unlikely through a transformer.

I missed that line in my initial read,
That is quite a classic description of one LED going rogue. Chances are it might only be one bulb requires replacement. I literally had that recently while I was soak testing a stage light after repair where I saw the bright flash out of the corner of my eye then the set of 3 LED glowed dim, just the one required replacement.

But again I'm not trying to say it's what has happened in your case.