Modes not changing?

I have done couple of dropins lately, and I'm having problems with changing modes.

101-AK with XP-G didn't chance modes. I finally got it to change when unscrewing the reflector almost all the way. After that it has worked. But my Nanjg 105(c?, the 2,8 amp driver from Shiningbeam, the one with the stars) + XM-L just does not change. It's on high, no matter how I hit the button. It's supposed to be lo-med-high.

I'm new at this stuff and have no idea what I'm doing wrong. Any advice? 105+XML T6 is a bright light, pulling close to 3 amps, but I have 1-mode XML already...

Make sure the reflector isn't touching the contacts on the LED (use a good isolation disk between the reflector and LED). It could be that there is some kind of alternative path from positive of the battery terminal that is bypassing the driver. Make sure your solder points haven't overflowed onto anything adjacent on the driver board itself. Sometimes the point where the leads are attached are very close to the edge of the board, but are not supposed to touch the outer ring. Check your soldering with a magifying lens.

Everytime that has happened to me it is because either the dropin or the tailcap switch are not screwed down tight enough. But I don't solder so if that is the issue *I'm clueless*

My U2 drop-in did that until I loosened the reflector. Even with the isolation disc it was mode-wonky when tightened all the way. Be-Seen actually pointed out the problem - in this case it may have been because the reflector base (the under side in particular) was for an XR-E and not hollow enough to not touch the electronics.


Folks , it happens when there is a short . Check you work ..

And yes often the reflector will crush the wires down creating a short against the base ....

Also a wire that is bare for to long , or really lumpy all over the place soldering .

1/ 1mm at the end of the wire should be bare .. Pre tin the end of the wire and the +- on the base .. This way you will use as little solder as possible to get the job done ...

2/ test for shorts before screwing down the reflector [ check your work as you go along ] or before soldering the driver in place .

3/ Tighten down the reflector gently , checking for shorts as you go

4/ When the pill is in the light , keep checking , Ive often found just tightening the head down , after wrapping the pill in Al-foil is enough to help create a short .

5/ I often superglue the reflector in place to stop in tightening and creating a short .

6/ Another thing to do is glue in some reflector stop blocks ... I cut up a fibe washer , thick enough to stop the reflector from crushing the wires , and glue them inside the pill on the base so the reflector will tighten up against the stop blocks rather than crushing the wires ...

Thanks for the input, once again.

This time the culprit was excessice soldering to ground the driver to pill. I was almost too frustrated to bother anymore tonight, but decided to check things according to brteds advice. I pulled the driver from the pill and checked soldering at the driver end of leads, but it didn't seem to interfere with the outer ring. Then I tested it by pulling wires directly from battery to driver positive spring and other to pill for ground. It worked as it was supposed to. All the modes were there. So I figured the reason must be the grounding to the pill. And to be honest there was a rather big blob of solder at the outside surface of the pill, where I'd grounded the driver. Some un-soldering magic and little blade action later it was sorted and now I have 3-mode XML. Perfect.

Fantastic. Glad you were able to get it sorted out. That's a really common problem when you're putting together drop-ins (at least for me).