Re: Fenix TK-40 Flickering
Okay, I'm surprised.
The center bar on my battery holder was not loose, so I didn't think this trick would apply.
But I was bored, so I took apart the battery-holder pretty thoroughly: all four hex-nuts on the bottom end, all four on the top end, i.e. the ones that are threaded onto the black rods where they come through the lucite end-caps.
(I did not remove any of the small philips-head screws that attach sheet-metal contact-plates to lucite).
With the four long black bars out, I then threaded the center bar out of the head-end lucite end-cap, cleaned the threads a bit with paper-towel, and reassembled the whole thing.
damned if it didn't work straight off, and keep working. I left it on all night on low, and it's working this morning. I just clicked it off, then clicked it through all of its modes, and it's working.
I am baffled by this, in part because I cannot see what electrical role the center bar and the four black cage bars play (the center one is bedded in lucite on the tail-end, so it is not part of any path from tail-end to head-end), and in part because I realize that I just don't understand the electrical pathway in this light *at all*.
Is any current flowing through the outer walls of this light? I used to spend a lot of time trying to clean up the threads on the battery-tube where the head threads on and where the tail-cap threads on, thinking I had bad contacts there--maybe that was irrelevant?
The battery holder itself has, on its head end, two coaxial contacts: the central coil spring is positive, and the outer sheet-metal spring is the negative. But then why are those two not constantly feeding current into the head? (Or perhaps they are, the so-called "parasitic drain").
What is the switch doing? On the tail-end lucite end-cap of the battery-holder there is a bright sheet-metal box with four tabs that are held down by all four lengthwise black bars. That little sheet-metal box is in physical contact with the spring coming from the clicky-switch in the tail. Is that doing any electrical work? I can't figure out a pathway. Are the long black bars conductors themselves?
Can any one explain to me what the electrical pathway is in this battery holder?
I assume it goes something like this:
1) the bulk of the current for powering the emitter is drawn from the two coaxial terminals on the head-end of the battery-holder.
2) but the switching happens electronically, by a pulse of current that starts here, goes around there, runs up to the switch, runs down the black bar, goes around the corner, stops for a drink, spirals around the threads, bounces off the backboard, and falls into the net. Or what?
Anyhow--it works! How the heck does it work??
