LED spot lights

[L Austin France]

Ah, but has every LED failed?
Lots of 'stuff' on youtube where individual LEDs are tested using a 3v button battery & two needles.
I seem to remember how they 'shorted out' (maybe) duff LEDs & the others worked.
Could be wrong of course but it was something like that.

[RobertArthur]

Once upon a time - not too much money - I tried to repair everything, mind over matter. Nowadays I'm faster with my verdict: damaged beyond repair. There are 28 leds in this array, many of them dead, a sandwich construction, not easy to solder those small smd components. One missing led link in such a series connection, leds connecting the sandwiched copper inside, okay, but so many....

[L Austin France]

Once upon a time - not too much money - I tried to repair everything, mind over matter. Nowadays I'm faster with my verdict: damaged beyond repair.

Absolutely but I still like to know why things have failed if my old brain can comprehend the reasons.
I've just bought a pack of 2 x 20w IP66 LED spots for 14€.
I needed one to brighten up a dead corner in the barn where Mme stores horse & dog feed.
Works a treat so far & for 7€ each I shan't lose any sleep if it packs up.
10 min job to change with WAGO connectors I now use all the time.

[RobertArthur]

The ever-expanding range of WAGO connectors rules the electric waves.....

[DaveW]

The spots can be quite susceptible to power surges unless you have them on a surge protector. I’ve had a couple go and it’s a toss up between surge protection or the cost of the led.

[RobertArthur]

@ L Austin France, we share one thing in common: also my old brain likes to know why things have failed. However, there may be a difference of opinion regarding the manner in which you wish to acquire that insight.

I'm hesitating: desolder all the 28 leds and surgery under a microscope and do some retro-engineering looking at both the component side and copper side (also smd components) of the little printed circuit board? It is too warm for my brain to decide.....The answer is blowing in the hot wind I'm afraid.

[RobertArthur]

Not bad at all, the design of the powersupply for these 28 leds: from the 230 V AC line the phase goes through a capacitor, a MOV (blue) takes care of overvoltages, to the input transformer. A capacitor of 0.1 µF/280 V at its output going to a second voltage step-up transformer. Diodes, smd resistors, caps and a little three-terminal voltage/current regulator. A nice electrolytic capacitor of 47 µF/160 V in the DC output. Not the standard 85º C temperature range, but 105º C.

Only problem: out of six bought in 2015 three of them ceased to be, dead as a doornail. The rise and fall, Humpty Dumpty, from ceiling to being grounded, still shining brightly thanks to the abundant sunlight. The Philips radio in the background, type B7X14A, Bi-Ampli Stereo/Reverbeo, output transformerless OTL design, two 800 Ohm dual-cone loudspeakers, around 1960, still does what its maker wanted, 65 years later. Interesting.