LED lens fell off

This morning I was doing some routine maintenance on my EDC Mini-Maglite with a Terralux TLE-5EX LED drop in upgrade bulb. As I was putting grease on the O-ring under the head, the hemispherical clear plastic lens on the Cree LED fell off. It seemed to be held in place over the LED by some soft, clear gel-like substance.

Is there any way to glue the lens back into the LED without affecting the light output? If so, what sort of glue should I use? I was thinking about maybe using a tiny bit of super glue or silicone caulking around its outer edge.

there isn't really an easy way to reattach the dome without losing more light output. Cree uses optical grade silicone.

there shouldn't be any hard using the LED without the lens, but I believe that OTF the light output will actually decrease.. the angle that the light is coming out is now not optimized for the reflector.

Ah, OK thanks for the answers. Hmmm...does anyone know where I can buy this optical grade silicone? Or is it even worth it to attempt to repair my Mini-Maglite's LED or would I come out ahead just by buying another new Terralux drop-in and write off the current one?

id try a drop of superglue carefully placed before id throw it away

If you can find the exact orientation of the lens and get it to fit back on perfectly I'd try using adhesive carefully placed around the edge, avoid the diode itself.

IMO, not worth trying to fix it. if it still works, it'd still use it

I also don't think it's worth fixing it. As long as the light still works and the beam pattern isn't too ugly, you should be fine. You might even get a bit more throw since the removal of the glass dome makes the apparent die size smaller.

I had one fall off a PD30s LED and as soon as it did the output was reduced by like 80% and it was a terrible yellow color.

Buy a new LED, desolder the old and solder in the new.

ouch... Yeah that happens. the LED domes are delicately held in place with optical grade silicone, so they are not really made for durability. I think Craig has the best advice, if it still works just use it till' it dies. Also, because its silicone, you can't re-adhere it back with anything else BUT silicone

So CA and epoxies are out. Furthermore, if you use CA anywhere near the LED it will fog over the dome. I found this one out the hard way and had to scrap an otherwise perfectly good XRE.

I don't believe those teralux drop ins can be easily repaired too. If you wanted to attempt an emitter swap, You need to heat the base of the XRE to ~200F (ballpark) and get the solder to flow. I don't think you can accomplish that without destroying the DC-DC circuit and pill assembly.

I have performed XRE transplants with varying degrees of success (honestly... more failures than success stories).

http://www.youtube.com/user/MuvoTX#p/u/5/rHyRLQexJpA

Thanks for the tips guys. Is this a common problem with LEDs in general or Cree LEDs specifically? I've never experienced it before, but I have to admit that I don't make it a habit of touching the LED domes on my other lights.

I didn't really touch the dome that hard this time either. It just sort of plopped off without any effort on my part.

Don't forget Mag has a nice warranty

Except that this is a terralux addon, not a stock mag dropin.


Yeah, this problem seems to happen most often to crees and sst50s , not Seoul and Philips

Whoops, didn't read that :x

I just emailed Terralux about what happened to my TLE-5EX LED. You guys were right and the light output decreased noticeably. I'll see if they can repair or replace it and post the results here.

I'm keeping my fingers crossed.

Terralux has good warranty service.

I've had two TLE5EX modules quit after several years of service. Each time I emailed Terralux, and each time Jennifer Brady sent me a new one with no questions asked (pretty good for something that has a one-year warranty). She did not want the old ones back.

Yours is still working, so they may just say run it till it quits and they'll replace it. Best case, they may send you a new one now and you still get to run your current one till it quits! Either way, they'll take care of you.

Update

I received the Terralux warranty request form in my email this past Tuesday and I filled it in and faxed it to them on Wednesday (yesterday.) They said that I did not have to send them the broken LED. I've got my fingers crossed that Terralux will stand behind their product.

What about that specific glue people have been using to glue tritium onto their lights? It's supposed to be optical grade, and dries perfectly clear and hard (sorry, but I forget the name of it)

*EDIT, it's called "Norland Optical Adhesive #61"

Locoboy5150 said:

Update

I received the Terralux warranty request form in my email this past Tuesday and I filled it in and faxed it to them on Wednesday (yesterday.) They said that I did not have to send them the broken LED. I've got my fingers crossed that Terralux will stand behind their product.

Click to expand...

Wow, that is pretty awesome! But, again, as kramer5150 stated, superglue will haze over anything that it is near---chemically induced permanent fog is one of the last things you need in a flashlight or lightsource! Good luck!!!

Trichrome that adhesive is called Norland61.

Thinking of it, it'll probably work. But you have to somehow keep the norland in place while curing it with UV