My old Petzl Myo XP headlamp had stopped working, so I took it apart to troubleshoot. I narrowed it down to a bad wire connecting the batteries to the circuit board. The wire looked fine from the outside, but no power was getting to the board. I desoldered the leads, cut off about 1/2″, stripped and resoldered, and then everything was fine again. While I had it apart, I noticed how easy it would be to replace the older LED with something newer and brighter.
I decided to replace the existing luxeon LED with a CREE P4. The CREE isn’t an exact fit with the optics, so the beam is more floody and has some annoying rings, but it is much brighter. I later discovered that an SSC P4 would have been a better choice, and is used in the newer version headlamp which is gray in color (mine is blue). I will be testing out the CREE at the Endorphin Fix 50hr adventure race this weekend. If I don’t like it, I’ll probably swap it out with an SSC.
Here’s a very quick overview of how to make your old light as good as new for only $4, instead of buying the new model for $85.
Tools and parts needed:
- T-6 torx driver
- soldering iron
- heatsink compound
- new LED “star”
Time: less than 30 minutes
The first step is to get it apart. Removing four torx screws and prying apart the housing easily gets you to the internals. From there, gently pry off the metal heatsink/plate. Next, the whole assembly of driver board, buttons, and LED can be wiggled out of the housing. Look at everything as you do this, because you want to put it back together the same way it came apart. It’s pretty dang easy, but since I’m not posting detailed pics, I just thought I should remind you.
The LED star can easily be removed with the soldering iron. Just heat up the contacts and pull it away.
I put a couple of dabs of solder on the new star before soldering to the existing wires. Be sure to get the polarity right! The star should have + and – markings.
At this point you can put in some batteries and test the light to make sure it works. If it doesn’t, I have no idea what you did wrong…sucks to be you!
Finally, start reassembling in reverse order. Be sure to put some heat sink compound on the back of the star before attaching the metal plate. Push the thermal resistor(?) up against the outside of the plate and squirt some heatsink compound around there too. Put the housing back together, screw the screws, and voila!..new and better light.
Here are before and after shots I took. The LED was set to medium, with the diffuser lens off/down. Both pics were taken at the same setting: 4 secs at F4
Other thoughts:
I’m not sure if the tiny heatsink in this model light will be sufficient for long runtimes while on high. I normally only use the medium setting anyway, so it should work for my purposes, especially with the increased output.
I have no idea what the long-term reliability will be like. I will try to post an update after a few months of use.
While looking for technical info on the newer, gray model headlamp, I found a post at candlepowerforums with a much more detailed tutorial of doing this mod. If any of this seems complicated, look there for more info.
Shane said I would like you, but this is ridiculous. Fixing your light!! Nice job, I am going to steel you posts and put them on our site under your name.
Great idea ! I have the same blue myo xp and will do the mod with a SSC.
Thank you for posting this.
Thanks muchly for this!
My lamp wasn’t working and by putting pressure on where the cable came out of the lamp casing it was clear that there was a loose or broken wire in there somewhere.
Your directions gave me the confidence to open the thing up and have a go at fixing it.
Sorted! There was a broken wire and after cutting a bit off both the red and the black wire and soldering the connections back on we are all systems go.
I should point out that I had to do the soldering twice as there is not much room for anything but the cleanest (or in my case second-time-luckyest) soldering so for others who plan on using these directions do take a good look at the angles of approach for the two wires as showen in the photos above.
Cheers!