Two purple, and two yellow tinted LEDs in Astrolux S41

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sac02
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Two purple, and two yellow tinted LEDs in Astrolux S41

I just noticed that my S41 has two LEDs with a distinct purple tint. The other two look yellowish, but I think that’s maybe OK. But I think there is an issue with the purple ones.

Removing the optic, it appears the optic has damaged the LEDs, although the LED with the most noticeable damage is not one of the purple ones. In the pics, the purple LEDs are the ones with the black sharpie dots next to them.

Thoughts? I could replace the LEDs, but my concern is that the optic damages them again.

djozz
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I found the best fix for this is carefully sand some material from the led-side of the optic, so that it by just clears the leds. I did not see any influence on the beam from it and it saves the leds. But you still want to be careful when closing up the head to not twist the optic (hold the optic in its final position with legs in the holes by pressing on top, and then carefully screw down the bezel around it).

sac02
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I was going to ask if adding a layer of CA glue to the bottom of the feet could work, but that option adds to the stack height of the pill and may result in the bezel not screwing down fully. So I will shave the bottom of the optic as you suggest.

Did the purple effect likely come from heat damage (being left on in high/turbo for too long), or mechanical damage (crushed by optic)?

Should I replace all four LEDs, or just the purple pair? Basically, if I replace just the purple pair and fix the optic, are the other two LEDs already damaged enough that they aren’t worth keeping? Is there really any way to know if they will die or survive indefinitely?

djozz
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-Purple leds signify that phosfor material has shifted by shearing of the dome, and the underlying blue led is partly bare.

-Yellowish leds signify that the phosfor has not shifted but the dome has come loose from the phosfor layer by shearing forces, this creates a ‘dedomed’ effect: reflection of light via the internal dome surface back into the phosfor, causing some output loss and tint shifting. But they could just keep working.

So all leds from your story sound to be damaged and yes, I would replace them all.

Edness
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replace them all with XP-L HI. More output and no need to worry about optics touching the domes.

sac02
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Edness wrote:
replace them all with XP-L HI. More output and no need to worry about optics touching the domes.

I really want my Nichia goodness from this light.

If my memory is correct, freeme had a standardized form to fill out to contact banggood for S41 issues. But I cannot find it with the search feature.

Does anyone have a link, or suggestion for how to pursue this with Banggood?

djozz
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If I remember well, this form was about the S41+S+, but the problems were the same that you have now.

Edit: looks like the pictures in the OP show the S41S, so never mind Smile

sac02
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Are you saying that based on the red MCPCB? I was looking through other threads and seeing mostly white MCPCBs in earlier S41 lights, and red MCPCBs in later S41S lights. Maybe I got updated internals somehow? It is an Astrolux S41, aluminum body version, purchased in late October 2016.

snakebite
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it almost looks like it was built with 2 different tints.
look closely at the tint of the phosphor.

Meelo
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When I used to buy 3aa magled’s, some would be purple, there was no consistency.