Started down the sidewalk a little while ago turned light on and went to click it to turbo and let it slip out of my hand.Can’t get it to come on now. so far i know it’s not the battery or the tailcap.
Doesn’t seem to be tailcap tube or battery. I changed from short tube to long tube and back again making sure everything was tight. I checked tailcap with dmm and it checked out fine.I took the lens out and leds and mcpcb looked fine wires where still connected .Only thing i haven’t done is take out driver.
Driver retaining ring tight?
Yes it’s tight, guess i’ll pull the driver this evening.
likely the driver with some broken wire or part
Does the battery have a huge dent in it? If it’s a protected battery, did you try another one?
I’ve seen one where a drop dislodged the emitter from the PCB… it actually broke the solder free.
Was it attaced with kids paper glue?
Sould never be possible.
Dang I hope you can make some pics of the inside of the head, sure it can be fixed, keep hope!
The good news is now you have an excuse for a D4.
OR
To mod the s41
Lol I already got a d4 and the s41 has a mtn 17 dd driver in it.
Have you tried blaming the Chinese 
?
did you connect a cell directly to the LEDs? (just a split sec to check if they light and so that you don’t blind yourself.)
Traditionally, we don’t ‘check the tailcap’ we remove the tailcap and connect cell to body to check if the light comes on. (Technically, i don’t think it’ll make a difference. 
)
Good luck with getting it up and running again.
This post is filed under LED Headlights. Am I missing something?