# XM-L Gone To Led Heaven



## moderator007 (Aug 27, 2011)

I have a custom hunting light that I made for a friend. The XM-L seems to have went to heaven. The light has 10 18650's wired 2s5p. The light was in the back seat and some how had got switched on under a jacket. The light had been running for some time when it was found. This light can run about 6 hours before dead.
Now the led seems to be dead. I reflowed it of the board and connected it directly to a power source and I get nothing. Looking at the XM-L I can see no visual signs of anything wrong. The light head was very hot to the touch when it was found on. I machined the head from 3 inch aluminum bar stock. So it took some heat to make all that aluminum get hot to the touch.
So do leds die without no signs of death?


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## Th232 (Aug 27, 2011)

Just to make sure, you were using a driver in this, right? What current was it running at?


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## moderator007 (Aug 27, 2011)

Yes constant current with constant voltage variable PWM output driver at 2.9 amps to the led. Everything still works but the led.


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## PCC (Aug 27, 2011)

I had an SST-90 (!) that died in a way that it didn't appear to have any damage, but, it wouldn't put out any light whatsoever. I looked at it under magnification and all of the bond wires were there and intact. I didn't try seeing if it was flowing any current or not, though, before throwing it away.


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## moderator007 (Aug 27, 2011)

The XM-L still has all the bond wires intact. What probably killed it was the heat. It couldn't breath. But I would have thought there would be some sort of visual signs of over heating. Unless its disconnected some where not visible.


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## Morelite (Aug 27, 2011)

moderator007 said:


> Yes constant current with constant voltage variable PWM output driver at 2.9 amps to the led. Everything still works but the led.


 
I'm interested in a driver like that, were did you find one?


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## moderator007 (Aug 27, 2011)

Morelite, I had to build it, well part of it. This was my very first post on cpf link here. Its really not that hard to build.


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## 2100 (Aug 29, 2011)

Do you have the emitter with you? Try to hit it softly with a hammer or something.  I revived mine this way, triple XM-L DD....twice! But i suspect that it was the bond wire.


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## JohnR66 (Aug 29, 2011)

Is the LED "dark conducting" or open circuit? If conducting, try giving it higher current in short bursts. Start low and work higher. You have nothing to lose. You may get it emitting light again but perhaps not at initial intensity.


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## moderator007 (Aug 31, 2011)

JohnR66 said:


> Is the LED "dark conducting" or open circuit? If conducting, try giving it higher current in short bursts. Start low and work higher. You have nothing to lose. You may get it emitting light again but perhaps not at initial intensity.


The led is conductive when tested. I tried at a higher current it did light up. But only one side of the phosphorous lights up. Upon a closer look at the bond wires i can see a little black spec on two of the bond wires. It did not light up were these two wires were. It lite up where the bond wire has no black spec. I can't see a break in the wire but i can see the black spec. I think she's dead. I going to put her to rest. 
Thanks for the replys.


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