XHP 50.2 dome detached - repair advice needed

Hey :blush:

The plastic/silicone dome fell off of my XHP 50.2 LED. How can I get it back on? It doesn’t stick anymore. Do I need some kind of glue or do I have to run the LED hot so that it will stick again?


It’s dead, you need to replace the LED.

Instant shaved dome —- Is it still working —no black spot on it

Or keep it?
he didn’t say his not working.
XHP 50.2 HI natural. :partying_face:

The LED still works. When I press the detached dome onto the LED it holds for a while. But when I shake the flashlight the dome falls off again. I switched the reflector of my Convoy M21B a couple of times. I have to switch the gasket around the LED as well. This time the dome detached when I tried to remove the gasket.

You need a new LED unless its not blue?, i done the exact same thing to my EA02 except i done it to three LEDs at once lol. If it doesn’t look bad just leave it with the dome of, the XHP looks okay with a shaved dome.

No blue ? I said dead because usually the phosphor comes off with the dome, but if it didn’t then yeah you can keep using it that way, more throwy and uniform beam.

Can I use the flashlight without a domed LED without any risk? What about the temperature and thermal regulation? Doesn’t the LED need the dome to dissipate heat or is it just attached to the LED to improve the color and light distribution?

The dome just affects beam characteristics and tint. You can safely run the light without it. Lots of people de-dome leds on purpose to increase the candela of their lights.

Thank you all very much for your kind replies!

It’s already night in Europe, so I just tested the de-domed flashlight. Sadly, the tint looks quite ugly now. I really enjoyed the very warm tone of the 3000K XHP 50.2, but now the tint is very cold and even seems a little bluish to me. I think I messed things up :person_facepalming:
Other people might still like the tint but I prefer 3000K.

There are single LEDs available in Convoy’s store: https://de.aliexpress.com/item/32960723533.html?spm=a2g0o.store_pc_groupList.8148356.54.14ce24bfo3FtsW

But I think I don’t have the tools and I lack the skill to replace the LED element. There has to be soldering work done I guess. Argh, what a pitty!

Great opportunity to learn a new skill, i must warn you its addictive lol.

I watched some YouTube videos last night. The work seems to be quiete easy for people who have the right tools and skills. A friend of mine could do the job. I ordered a replacement from Convoy, i.e. a XHP 50.2 LED on a MCPCB/copper board. I still can’t believe the magnitude of damage that I have done :innocent:

Thank you guys!

When the dome came off it removed some of the phosphor layer with it.

LEDs of the type used to produce light for flashlights consist of a blue LED coated with a layer of yellow phosphor. The LED emits blue light, some of which is absorbed by the phosphor which then emits red and green (and other related colors). The result melds together to form white light.

Depending on the phosphor mix the output might be 3000K or 6000K, but the same method is used to produce the light.

In your light, when the XHP50.2’s dome fell off it probably took some of the yellow phosphor layer with it. Result is more of the blue let is getting through. Less phosphor means less of the warmer colors. Result is color temperature of the LED drops and you no longer have the 3000K you prefer.

Unfortunately, there is no way to stick the dome back on. High-powered LEDs found in flashlights produce a tremendous amount of heat while in operation. No commonly available clear glue would stick through that kind of heat. You need to replace the LED.

I just screwed off the MCPCB/copper board to see whats beneath it. There is some gray fluid/cream between the MCPCB and the driver(?). What about that gray cream? Is it thermal paste like used for computers? I have some “Arctic MX-4 Thermal Compound” that I used to renew my Lenovo ThinkPad. Can I use such thermal paste or do I need a specific product for flashlights/LEDs?

What about the operational procedure? Can I do it like that?

  1. use a soldering iron to detach the wires from the MCPCB
  2. unscrew the MCPCB and remove it
  3. remove the old thermal paste from the MCPCB and the driver
  4. attach fresh thermal paste to the MCPCB and the driver
  5. attach and tighten the replacement MCPCB
  6. use a soldering iron to connect the two wires to the MCPCB

Is that it?

Before you install the MCPCB — Tin the 2 solder points where the wires go — I would sand the underside of the MCPCB with some 1000 grit on a flat surface— to make sure it’s flat

Thank you! I will give it a try. Now I have to wait. It will take some weeks before the replacement LED will arrive.

Are you in the States — Mountain Electronics would have been a lot quicker

Nah, kind greetings from Germany to you :face_with_monocle:
I still got another M21B. It’s a 4000K XHP 50.2. So I’m not running empty. I just prefer the warmer 3000K tint. Convoy will send the replacement free of charge.

At least you got a shot at getting it —- Here in the States no telling how long it would take

Hard to get a good shiny solder joint with the board sitting in the thermal paste on the shelf. I was advised to slightly lift the board to break the thermal path while soldering the wires. I de domed a xhp50 by accident once too.