I’m not sure what happened, or what I did wrong here. Received my Convoy T3 a couple weeks ago, and decided to dedome my 519a 4500k. Followed instructions and watched multiple videos. Seemed easy enough.
Being new to the hobby I didn’t have a battery charger yet. So while waiting for the Vapcell U2 I had been using a standard AA cell. Put off a beautiful rosy beam that I loved!!
Fast forward to today and the charger showed up, so I charged my 14500 Vapcell. Threw it into the light and immediately noticed a cooler color hue and much brighter than when using the AA. I had it on high for about 15 seconds and the light got extremely warm and noticed the hot spot seemed to change. Then i noticed this…
Did I fry the emitter!?!? I don’t understand what happened. Did dedoming cause this? I wouldnt think a fully charged cell that came with the light would cause this. Please let me know what went wrong, or what you think went wrong here? I’d like to learn from this mistake and fix this problem if I could.
Probably the heatsink pad on the underside of the emitter isn’t fully soldered to the star. It could have come like this from the factory. Or possibly if you overheated it while dedoming maybe you melted the solder and knocked the LED out of position slightly.
Dedoming alone shouldn’t cause a 519a to degrade like that.
I only heated for about 10-15 seconds prior to dedoming. I’m going to assume this won’t be covered by warranty, as I likely caused this issue myself. Definetly feeling a bit down and defeated. Especially since I have zero soldering experience and assume that would be required in solving the problem. Was pretty excited to get the proper cell charged, and then it all went to hell within a minute later. Happy Monday!
There’s another layer of clear stuff on the LED under the dome. Unless you damaged that during de-doming (which should be visible to the eye) this was not why the LED fried.
Could be a number of things, bad heat sinking like mentioned above or something could be wrong with the driver.
From my limited experience, LED’S blue up when you either remove the phosphor, OR the light is overvolted. I can’t imagine a situation where the light would overvolt the LED before frying the driver…unless the driver got confused and hit the LED with 3x3.7V or something…
In the picture posted by OP, the phosphor is clearly burnt. It looks completely different when phosphor is scraped off revealing the blue LED beneath.
Easiest way I’ve found to dedome a 519a is to simply run the light for 30 seconds or so to warm up the LED, then use the back of a flat toothpick to push the dome off sideways. Usually it comes right off on the first try. No need for a soldering iron at all.
There’s no difference. Overvoltage will lead to ocercurrent, and in order to overcurrent the LED you will need more voltage. I don’t believe that this LED was overloaded at all in this light.
The LED die is bonded to the substrate, but this bond can be damaged if excessive mechanical stress (downard pressure or lift) is applied to its surface, and when it gets damaged the die can no longer transfer heat properly to the package, and it might lead to overheating of the die. Every LED is different though so there’s no metric of force that can be applied to the LED surface. Instead, the manufacturer always say “avoid touching the light emitting surface”, so it’s good practice that we follow this.
This can be the case. Excessive pressure (downard or lift) applied to the die, die bond to the package cracks, insufficient heat conductivity leads to localized overheat and damage to the device.
When I dedomed, I honestly did not notice if there was any kind of glass on the phosphor. Though when looking at it, it doesn’t appear that there is. So that could certainly be the problem.
I find it puzzling because everything was fine when I used the standard AA cell. Used that for around 2 weeks with no issues. Then the minute I put the 14500 back in after charging for the first time. This happened.
Without the glass lens over the phosphor, absolutely.
Edit:
I cracked the glass lens on a 519A 5000K while dedomeing it, I put it in a S2+ with a 8x7135 driver nerfed to 50% max and it’s been working fine for a while now.
I see OP is not sure if there is glass on the dedomed LED… maybe he has not learned to see the reflection, at the proper angle…
He could probably reinspect and determine if there is in fact glass there.
I have never seen a dedomed 519a without glass over the phosphor, but I make a point of angling the surface to see the reflection, so I can tell if it needs cleaning.
@TkoK83Spy did the burn on LiIon High mode, happen when the reflector lens and bezel were not installed? Was the battery a Vapcel H10?
