Need help! Lumintop FW3

Hello all
I bought an FW3 from Illumin in copper
Came today
Their service was great, BUT
The light does not work!
On inserting a battery (FROM THE FRONT) I get one quick flash when the top is about half screwed down.
Just does not turn on at all.
Used a Samsung 30Q and an Orbitronics high drain, no difference,
Everything is screwed down tight, tail cap was NOT removed.
Anyone got any ideas???

Couple possible troubleshooting steps to take:
1. Remove the head and battery.
2. Completely unscrew the tailcap (Do this over a table so no parts get lost)
3. Reseat the command tube (black tube inside the battery tube)
4. Verify the nub between the switch and rubber is sitting centered in the hole (check THIS post for visual confirmation and more instructions)
5. After you reassemble the tail switch and have the command tube reseated, tighten the tailcap all the way down.
6. Check the head driver retaining ring, loosen and tighten.
7. Test light.

It started to work after driving me nuts all afternoon.
Here is what I think is the actual problem!
The inner tube does not align properly with the contact rings on the tail cap and especially on the head. I had the retaining ring off and on a couple of times, finally I loosened it and made sure the board was centered. VOILA it works! Then I pulled the battery and reinstalled, did not work!
A couple of on and off of the cap and it started working.
So probably an issue of the contact between the rings and the tube.

So my next question is, why are they so intent about telling you not to remove the tail cap, then you have to take it off to get the light to work. And to remove the clip.
What is so special about the tail cap?
I took it apart and put it back together (switch was NOT the issue) and it was easy, no sweat. Are the threads going to wear out or something.
BTW, with the clip removed the tail cap seems to screw in slightly more, giving better contact. Sometimes the quarter turn to lock out does not work now, it stays lit until the head is more than 2/3 off!

As discussed in the linked thread from CalvinIS, the components that makeup the tail switch are held in place with the friction of the tailcap and body screwed together. One of the most important components of the tail switch is a little plastic nub “nubbin” that can get lost very easily if the components of the tail switch fallout when you remove the tailcap, then the flashlight will no longer turn on. Nothings is stopping you from changing the battery from the tailcap end, but if you lose the nubbin, and are left with a nonworking flashlight it’s on you. I believe that the flashlight was designed for people to use the four-click lockout that’s built into the UI.

On the light that was delivered to me today, the assembly is held together by a ring, just like on the front.
I guess they changed it, no reason for that disclaimer to be in the box any more. The switch will NOT fall apart unless you unscrew the lock ring.

However the mechanical lockout does not always work. Sometimes I can almost get the head totally off and the light remains on - of course the switch does not work. Suspect that something is shorting out. But there should not be current in the threads since it is carried by the inner tube which should not contact the body. Although it probably does when partly unscrewed.

It is an electronic switch. This e-switch does not transfer power, but only the signals (to power on/of etc).
If you execute an old fashioned lockout (¼ turn), you disengage the e-switch, not the power transfer.
You already found out that the power is only interrupted when the head almost comes off.
That’s why there is a software lockout by the e-switch. Four clicks when power is OFF.
When the lockout is activated, the switch acts as a momentary switch (press=on), with moon/low as result.

It’s a necessary aspect of the light’s design that there is no practical physical lockout. I can unscrew the head on mine several turns while its on before it shuts off.

Power is flowing through the threads of the flashlight, the inner tube carries the signal from the switch. It will definitely have current in the threads when partly unscrewed.

You are correct of course. But you said it way better than I could.
So, it appears that the issue was that I was getting power, but the switch could not communicate due to the driver being off center.
That being said, I want to say again: There is a lock ring for the switch. The tail cap, at least on mine, can be removed at will.

And another question:
I have it set to ramping, but at several points going up or down there is a double blink. Did I manage to hit something different than stepless ramping? I have several lights with this system, but I never really messed with it, I am happy with the default settings. Or did I somehow manage to get it off default?

Not wanting to call anybody a fool, the design of the rear part of the light is not totally fool proof.
When someone tries to use it in a way it was never designed for.
Flawless operation of the light depends on the inner tube being parallel with the outer tube (body).
And because the inner tube is not secured, alignment is challenged every time you remove the tail cap.
So the best advice is to leave that part of the light alone if it is functioning well.
(remember the old Zen matra: if it works, don’t fix it)

Furthermore: the rear threads are fine and tri-angular. And are really not designed for frequent usage.
The front threads are course and square. To last longer if you have to change batteries often.

The FW3A uses a FET+7+1 driver. So, three power channels:

1xAMC7135 chip for 0 to 350mA
7xAMC7135 chips for 350mA to 2.8 A
FET for 2.8 A to full power (direct drive)

My best guess is that you see a double flash every time you “switch into next gear”.

Thank you

It is not foolish on my part to receive a new light with a written warning against taking off the tail cap, then receiving instructions from the seller (above) to take off the tail cap LOL.
Apparently they started putting a lock ring on there because people were losing switch parts.

Sounds contradictory. But not quite, when you think about it.
The note was to leave the tail cap alone, assuming that the delicate fine tuning was a success.
Then the Zen mantra applies: if it works, don’t fix it.
But if it does not work, the advice of the seller is the best: re-assemble the tail cap combo (very carefully).

Not to draw out this thread, but now that the light is working WOW. Just wow.
It is brighter than my Rofis MR70, which WAS my fave small light.
It just got overtaken. The output of this light is just astounding.
That being said, it does step down quickly and gets HOT. And I do mean HOT.
Still way smaller and lighter than the Rofis. I think I will keep it.