Dedomed XM-L2 U4 1A Issues

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djburkes
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Dedomed XM-L2 U4 1A Issues

Has anyone had any problems with dedomed XM-L2 U4 1As lately? The last 3 that I’ve dedomed (with gas) have popped on me. I’m using one of the newer fet+1 drivers from mtn with 22awg wire. Each one has popped at the bond wires. Both wires were burned through on the first two, the third still has one intact and the led barely lights up. One was on a 20mm tpad, one was on a 20mm noctigon, the third one was on a 14mm tpad. I’ve never had this issue with them before. I used a Samsung 30Q each time as well.

Mitko
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U4 binned XMLs are sometimes very sensitive to voltage( and heat)- some batches will pop up great time, especialy if direct driven
That will happen also if they overstayed in the jar

Nasty buggers they are….yet they run very cool when overdriven

And yes, it happened to me, lately nope but i depleted my u4 1a long time ago, using 1C atm

djburkes
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I’m gonna try to dedome my last one with heat. We’ll see how it does.

djburkes
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The hot dedome worked…hello Eagletac M25C2 Turbo with a fet+1 and dedomed XM-L2 U4 1A!!

Swib
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Very nice djburkes. Focus looks great too. Thumbs Up

If you don’t like what it looks like on the wall, take it outside.

dhvl1357
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djburkes wrote:
I’m gonna try to dedome my last one with heat. We’ll see how it does.

Pardon the noob question, but does that mean you run the led out of the heatsink to heat it up and then slice off the dome with a blade?

Slow is smooth; smooth is fast.

djburkes
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dhvl1357 wrote:
djburkes wrote:
I’m gonna try to dedome my last one with heat. We’ll see how it does.

Pardon the noob question, but does that mean you run the led out of the heatsink to heat it up and then slice off the dome with a blade?

Yeah, just connect a couple of leads to the mcpcb that the LED is reflowed to and connect the other ends to a battery. Turn it on for about 15-20 seconds and slice the corners. Turn it on for about 15-20 seconds again and slice under the dome towards the bond wires and lift before you get there so you don’t break the wires. Then carefully clean off any left over residue. There’s a few vids floating around of members hot dedoming.

dhvl1357
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djburkes wrote:
Yeah, just connect a couple of leads to the mcpcb that the LED is reflowed to and connect the other ends to a battery. Turn it on for about 15-20 seconds and slice the corners. Turn it on for about 15-20 seconds again and slice under the dome towards the bond wires and lift before you get there so you don’t break the wires. Then carefully clean off any left over residue. There’s a few vids floating around of members hot dedoming.

Thanks, that info is much appreciated!

Cheers.

Slow is smooth; smooth is fast.

LightRider
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djburkes wrote:
dhvl1357 wrote:
djburkes wrote:
I’m gonna try to dedome my last one with heat. We’ll see how it does.

Pardon the noob question, but does that mean you run the led out of the heatsink to heat it up and then slice off the dome with a blade?

Yeah, just connect a couple of leads to the mcpcb that the LED is reflowed to and connect the other ends to a battery. Turn it on for about 15-20 seconds and slice the corners. Turn it on for about 15-20 seconds again and slice under the dome towards the bond wires and lift before you get there so you don’t break the wires. Then carefully clean off any left over residue. There’s a few vids floating around of members hot dedoming.

So do you lift from the side with the bond wires or lift up from the opposite side then flip it towards the bond wires?

djburkes
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LightRider wrote:
djburkes wrote:
dhvl1357 wrote:
djburkes wrote:
I’m gonna try to dedome my last one with heat. We’ll see how it does.

Pardon the noob question, but does that mean you run the led out of the heatsink to heat it up and then slice off the dome with a blade?

Yeah, just connect a couple of leads to the mcpcb that the LED is reflowed to and connect the other ends to a battery. Turn it on for about 15-20 seconds and slice the corners. Turn it on for about 15-20 seconds again and slice under the dome towards the bond wires and lift before you get there so you don’t break the wires. Then carefully clean off any left over residue. There’s a few vids floating around of members hot dedoming.

So do you lift from the side with the bond wires or lift up from the opposite side then flip it towards the bond wires?

From the opposite side towards the bond wires.

LightRider
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Ok. That’s what I thought but wasn’t sure

ARsee
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Good info