Driver stuck in low mode

Was trying to do the this mt-g2 c8 mod using a regular nanjg 105c driver. Had problems with getting it to work but finally did after failing the first couple of times.

Well it worked while when I tested it in the pill but outside of the flashlight body. But when I finally installed it in the body, I found that using 2 18350 cells was a little too long for the c8 to handle. I had trouble screwing in the tailcap although the light still worked when i used it without the tailcap and just shorted the battery to body with a wire.

Dumbly, I tried to squeeze the batteries in and screwed the tailcap on. I think I used a little too much force and might have damaged something. Now the driver only gives me a low mode and I can’t change modes at all. Would anyone have any idea which component might have been damaged and whether its fixable?

Thanks heaps

Have you tried taking the pill out of the light, and see what happens?

Something in the head is shorting. Take it apart and inspect. Make sure the reflector isn’t shorting on the lead contacts.

If your light has a brass cap covering the switch spring, take it off. If it has one of those really long springs, replace it, or cut it down. The same goes for the driver spring.

The light behaves the same way outside of the pill too. So I don’t think it’s a problem with the reflector. Anyway I’m pretty sure the reflector is not shorting the star.

I’ve removed the brass cover and cut the spring. Will check more closely for shorts. I’ve already had a look and can’t find anything obvious. I guess I need to look harder.

Thanks guys for the advice.

I have killed nanjgs in a similiar way too, not sure what happened but some die while trying to get modding details figured out.

If the driver's physically broken it doesn't much matter which component is causing the problem.

Even shortening the pill this much, and using solder instead of a spring, and moving the zener to the inside instead of on top of the capacitor, it's still not quite enough space for protected 18350s, you also have to go through the tailcap parts and slim down everything you can.

Ah that’s actually a good idea shortening the pill that way. I guess I’ll get another driver then. Man this mod is really burning through nanjgs. It’s the third one I’ve busted already. Oh well I guess it’s good practice.

Quick question, can the Zener be connected one side to the inner part of the capacitor and the other side to the 1st star? Would that serve the same purpose?

It can go anywhere that connects MCU pin#8 to GND. I did it this way:

See the napkin diagram for the 105C schematic: