Unable to program 4Sevens Quark 123² Tactical anymore

[bootsy]

Hey guys, I got a problem with my beloved flashlight :sick2:

For around two years I own a Quark 123² Tactical and I was totally satisfied with it - until now. For some reason I am unable to enter programming mode any longer. However loose and tightened settings are somehow the same, too. Before it was programmed to tightened: mid, loose: moonlight.
I even replaced batteries with new 4sevens CR123A Lithium batteries (bought two years ago but still should be fine!) without any difference.

Does anyone have an advice to me, what to do, what to check?

Thanks a lot,
Robert

 

[Hondo]

Welcome to CPF, Robert! Try this:

Remove the head, clean everything you can off of the head and body threads. Then clean the end of the body tube, where it makes contact up inside the head on the PCB (printed circuit board). Last, clean the trace on the outside edge of the PCB where the body will contact (Q-tips work good). Re-assemble, and try again. If that works, open it again and apply a light amount of lube to the threads and O-ring. I use Nyogel now, but never hurt an O-ring using Vaseline. Plenty of threads here on the different lubes you can use, but try it dry and clean first.

 

[oKtosiTe]

Just to be sure: what's the one single mode you're able to access now, mid or moonlight?

 

[bootsy]

Hey guys, thanks for the warm welcome. I really appreciate it :thumbsup:

@Hondo: I cleaned the threads very well before and thought that would be sufficient but apparently it wasn't. Even without getting much dirt on the qtips apparently that made a difference. However, everything is back to normal now, thanks a lot. :thanks:

@oKtosiTe: Mid mode - I was about to buy another new battery pack just to make sure the it's not a current issue because of depleted batteries.

While cleaning the tube one thought came to my mind: how does the chip recognizes when the head is loose/tightened?

 

[oKtosiTe]

While cleaning the tube one thought came to my mind: how does the chip recognizes when the head is loose/tightened?

If you look inside the head, You will see the circle in the middle (+ contact point), a U-shaped protrusion at both sides (reverse polarity protection), and around that (separate from the threads) a secondary negative circuit ring. This ring should only be touching the battery tube, completing the secondary negative circuit, when the head is fully screwed down, letting the chip know the head is screwed down (both negative circuits completed). It's a fairly common system, and not an uncommon cause for problems.
It's usually easy to resolve though, by removing dirt/oxidation from both this ring and the "upper" edge of the battery tube.

 

[bootsy]

Thanks for the explanation!

(issue resolved, for me thread can be closed)

 

[oKtosiTe]

Thanks for the explanation!

Glad you liked it. :welcome: