I have a mod I've been slowly working on where I put this XM-L DX module into a Maglite running on (2) 18650's. I messed up the original Mag switch and replaced it with a rocker switch. The flashlight was working just fine (going through all 5 modes) for awhile. I then got tired of the way the rocker switch was so difficult to use and decided to replace it with a clicky switch.
This worked out really well but now that it's all back together it only has 1 mode! Tailcap current is showing 0.34A. No matter what I do it won't switch modes! I even took the tailcap off, pulled the module out and ran a wire directly from battery negative to the driver negative connection - still only the 1 same mode! WTH??? I could understand if I had no power to the LED, or it was direct driving, but why only 0.34A?
Any thoughts? What can I check? Do I suspect the driver is bad and replace it? I never ran this light for more than 5 minutes at a time. And the driver is directly wired for positive (from switch) and negative (soldered on body contact).
I never had this drop-in apart - i.e. I never accessed the component side. However do you think trying to heat up the brass heatsink and soldering my negative lead could have caused something on the other side to shift? My soldering iron is only 25 watt and can hardly heat that brass and sometimes gets stuck. In order for me to remove the driver I'd have to use a propane torch and probably destroy tge driver in the process (maybe even the LED). I'm not too keen on trying to cut the solder off with an x-acto and risk slicing my fingers off!
My batteries are at 3.94v so it shouldn't be battery related, should it?
Probably not battery related. A 25W soldering iron IMO is fine enough. I have a 25W hand held one and worked for me for more than a year. However i switched recently to a soldering station with temp regulation. A freind gifted his own to me as he never used it. Anyway, it is simple to remove the driver from the dropin. Upon heating the solder a bit try to pry out the driver with tiny screwdrivers (watch repair sizes are excellent). Often poorly soldered dropins can be pry opened without even making a dent on the driver providing you have sharp tiny flat screwdrivers. Check if the driver has any holes... those are evem more easy to take apart, sometimes even without any heating at all (if you don't care for the driver). I have removed at least 20 drivers with nothing more than a screwdriver or two. More often than not the driver could easily be recycled for another project if need be. Rarely was whacked beyond usability.
I don’t know about Maglite drop-ins but I’ve taken out drivers in smaller pills just using a little desoldering braid.
Usually there is just a bit on a couple of areas and after that it’s just a press fit. I can usually get a small knife blade under one edge and it just pops out.
I don’t have good soldering skills and the tediousness of working with the small wires means I don’t really do this kind of modding but I have done the part described above. It’s not hard and would rarely be destructive.
Hmm, interesting. Tried to de-solder driver tonight and found out that just by resoldering the wired connections to the backside of the driver I was able to get the modes back. However, they seem to go away (back to single low mode) after just a minute or two (by the time I get the bezel back on)! I know electronics seem to fail from heat, but in this case it's almost failing from not being hot! And I narrowed it down to my positive lead. If I apply the iron to this lead at back of driver modes come back - very repeatable.
What the heck? Any ideas? I have now brought the light inside the house out of the cold to bring it (& batteries) up to room temperature.
Oh, and my iron won't heat the driver enough to remove all the solder on the negative lead. I would need to use a torch, larger iron, or grind it off.
As metal expands when heated the change in temp caused by the iron could be bridging a hairline crack that is preventing the mode changes.
You might also find that when it warms up in your house this also temporarily solves the problem because the hairline crack is only appearing when the circuit gets cold and the metal is contracting.
This could be solder or even a track on the board, try setting your dmm to ohms and confirming continuity where it looks like a solid join/track.
I haven't heated it up again since the last time I got it working, thought I had it fixed, and re-assembled. I'm going to try a few other tricks with heating it up when I get a chance again before I proceed with removing it.
Well the flashlight sat in the house all day with the batteries removed. Just for the heck of it I put the batteries in just now and tried it and it's working fine! Every attempt and it works fine through the modes! So what's this mean? Guess I'll keep randomly trying it and maybe set it out in the cold again and see if that triggers it not to work. (It did sit for about 10 hours overnight and didn't work - not sure why it needed 20+ hours.)
You will never know of have peace of mind if you don't unsolder it and reassemble properly. Maybe a wire insulation failed and a tiny "hair" of wire shorts the driver (the 1 mode). Do not worry if somethign eludes you, we are here to help. Just don't overheat altogether too much.
Well, I keep trying it out and so far it's working although it seems like the mode memory is gone (I swear it worked before and worked really quickly after turn-off.) I haven't let the light get that cold, but it did sit in my car all day (Avg 35 degrees F today) and the body was cold when I got back to it. I'm not going to do anything unless it quits again.