Thorfire TK4A go boom... (fixed, resolved!)

I don’t mind the slow mode-changes, but I’m pretty disappointed that it could just up and die like that. It’s got to be something simple and stoopit, and all I did so far was a visual inspection. Don’t want to unsolder the mcpcb yet ’til I hear from TF. The return-deadline is the end of the month, so I want to see what they’d say, first.

I’d still very much rather have a replacement than a refund, as it’s quite a nice light when it works. :smiley:

Hell, if it’s something I can repair, eg, if I could get a driver board to throw in there just for s&g and try it, I’d be willing to.

Maybe I should drop the other one I got onto a laptop and see if that one breaks, too. :laughing:

You would expect a more robust product for a light that costs north of $40 without batteries. The Thorfire website claims a “20 year lifetime” so maybe you can ask for a warranty replacement 404 It is no longer available on Amazon or eBay but the same light is sold by ThruNite as the TN4A light for only $56 https://www.ebay.com/itm/ThruNite-TN4A-NW-1150Lumen-XP-L-V6-LED-Flashlight-powered-by-4-AA-batteries/252223809230?epid=7011379869&hash=item3ab9b5e6ce:g:l0QAAOSwHPlWey6~. Obviously both companies buy them from the same manufacturer but with different brand names on the barrel.

Actually there is very little in common between the ThorFire TK4A and the ThruNite TN4A aside from similar names. Completely different interfaces, and bodies. For instance, if I recall correctly the ThorFire has the batteries inserted directly into the body while the ThruNite has a separate battery carrier. I actually found the UI of the ThorFire to be much more intuitive than the ThruNite.

Wellp, I got mine for like 15bux each on sale. :smiley:

That’s why I’m not going to cry myself to sleep at night over it, but as I mentioned, I’d much rather get a replacement vs refund. I genuinely like the little critter.

Dunno the Thrunite, but the TK4A is clones with the Sofirn SF11. Chicken, egg, no idea which came first… :smiley:

Either way, it’s a nice light, great feel in the hand, solid, just looks beautiful and sleek, just the right amount of “bling” (notches, knurling, etc.) to give it some personality without being all in-yo-face.

I bought the beasties just to burn off an assload of unopened in-the-case AAs I unearthed (good God, like 100 at least) that’d otherwise just go to Alkaleak Heaven without doing anything useful. But I ended up liking them. A lot.

Dunno, I’m just kinda bummed that it could be killed by a Dell. Who’d a thunk it?

Well that sucks man. Mine hasn’t been used much at all but still works. I had mine apart when I first got it, but can not remember snything about the design or how it’s made inside other than the missing screw on the MCPCB that I replaced…

Oh, just went back over the TF thread and I also swapped out the reflector and went to XP-L HI. Did some work on mine but still cant remember how it’s made inside. :smiley:

poped mine open… and starting to remember… the LED board sits on a floating pill, need to desolder the wires, remove the floating pill to get driver out. Driver is screwed to the tube and comes out the reflector end. E-SW board is mounted vertically to the driver and perhaps the solder joints cracked on the fall.
Starting to recall more bout it… mine has periodic issues where the tail cap is removed and occasionally does not turn back on when it is replaced. Just try it again till it works. I have no idea why.

Yep, that all fits with what I’ve seen. Only saw 1 screw holding in the driver board, opposite the switch. I only wanted to do a visual first, see if anything obvious would clue me in. Eg, a toroid flapping around on 1 wire, loose piece of solder that may’ve cracked off, etc.

I’ll wait ’til I hear back from TF before I go hacking away at it. Don’t wanna void any warranty…

After reading about the Lightbringer’s Go Boom story, holding the flashlight body in the right hand the head was lightly, gently tapped against the left open palm. When switch was pressed, no light even the switch. Got weird operations when pressed long, short, double. Opened and check the battery - all 1.46v. Put them back in, now get red switch light to boot and would not turn on except light flash. Thought I ruined it. Put fresh batteries in normal operation returned.

Changed to the old batteries and got back the normal operation, to my great relief. Hope somebody get some theory on what the cause is when Go Boom.

Son… of… a… beeyotch.

That worked!

Brand new cells in, snug up everything, press button… nothing. Wellp, what’ve I got to lose? Started slapping it silly on my palm… north side, south side, east, west, repeatedly, then all of a sudden… let there be light!

I’m going through the cycles, it goes through all 4 just fine, turns off, turns back on, more cycles, doubleclick for strobe, back, on, off, etc. Seems to be back to its old “normal” self.

Now to go ice my palm…

Okay, put back the semi-old cells, still worked.

Ain’t gonna risk any cells leaking, so ditched the 1.3x and 1.4x cells and put the three 1.5x cells, with one 1.5x new one. Still works.

Thanks, dewd, that so fixed it! :laughing:

I’ll burn down the other cells in a 1-cell light…

Hmm, still not quite sure if I should be happy or disturbed by what happened. :o

Thats kinda what I have been experiencing too. But I thought it was tail cap related contact issues.
Also wonder if it is some LVP triggering from poor or lost battery contact. I am running NiMh 1.2V so that has crossed my mind too. Perhaps the slightly lower batt voltage shuts it off and it gets restored if very fresh batts are replaced.

Glad its alive again. Will stay tuned to see if anyone comes up with a definitive answer/solution.

A coupla things came to mind.

First, I was running it down into the yellow, as I wasn’t about to waste cells with at least some oomf left in them.

But it went to red and then dead very quickly. Ie, it hung in yellow for a long time, no problem, but as soon as it dropped to red, it shut off very quickly, as in a matter of seconds. Yellow, blink red, off. I’m thinking at least one cell (weakest) got reverse-charged while others still were in the 1.3x if not 1.4x range.

One cell was definitely leaking, and another started showing signs of popping its seams at the negative end. Garbage.

Second, in the tailcap, one of the “buttons” (not the springs!) got… brown. Hmm, leaking from the pointy end? So right there, that might’ve oxidised it and increased its resistance. Note to self: next time check all the cells for a weak-link, and don’t assume they’ll all burn down equally.

But with new cells, it worked just fine, even on its brightest setting. The button was still making decent contact, apparently. Think I’ll lightly sand it anyway, just for s&g, and to make it nice and shiny again. :smiley:

…or maybe change your laptop? Find another brand that is flashlight-friendly? :slight_smile:

Very strange issue. Must find out the weak point, else it might happen again.

I had the benefit of getting the red low battery warning.

Since yours worked after trying out with new batteries, resetting the battery check circuitry, somebody might look into the design.

(Wonder if the reports of malfunction in the Amazon reviews have anything to do with this problem.)

[EDIT]
Did not see the latest posts.
May edit later.

I find that the the Thorfire TK4A doesn’t give you much warning when the LED goes red. At that point, the batteries are just about dead. IIRC, it’s something like:

Green: 3.6v or higher
Orange: 3.2v - 3.6v
Red: less than 3.2v

Since it uses 4 cells, red means that each cell is down to 0.8v or less (average). I use Eneloops, so at 0.8v, there’s hardly any charge left in them.

I think the design works okay if you’re using the light on max, because then there’s enough voltage sag in the batteries to give you a bit more warning. But if you’re using the light on a lower mode, there’s very little sag and so you get very little warning.

Battery Capacity Display is given as %, not volt.

The light will displaying “Green”, if the battery capacity is higher than 60%.
If it is lower than 60%, it will turn to “Orange”.
When it less than 15%, it will changed to “Red”.

Hmmm, okay, I must be thinking about another one of my 4xAA lights. Sunwayman D40A, perhaps?

Anyway, my TK4A certainly does not go orange at 60, unless I’m running it on max. It’s probably closer to 10 or 20% remaining capacity. They’re basing it on voltage when they change the LED color; what that voltage is I don’t know.

Thanks for posting a resolution. I’m glad it was an easy fix. Still doesn’t address the issue. I got a SF11 that would turn itself on, and then switch modes all on it’s own. Couldn’t turn it off, without unscrewing the tailcap. Sofirn sent a replacement ASAP, that works fine. I was only responding because my wife was putting on her socks this morning, and bumped the table. The SF11 tipped, rolled off the table, and hit her pinky toe. She went to work. When she got home, and took her sock off , BOOM Her whole toe is purple. Stupid me, asked if the light still worked :person_facepalming:
I didn’t say it, but was thinking, you’re lucky it wasn’t the Q8 :smiley:

Actually, I’m not sure if the batteries were the issue, as it was still quite dead after I swapped cells, and only came back to life after I started slapping it silly. Well, slapping my palm silly with it. Ow.

Either way, whether it’s the batteries, or the percussive therapy, or just shaking out the evil spirits, I don’t particularly care as long as the little beastie works again.

Okay, I’m still more than a little disturbed as to why it went mental after being… not even dropped so much as knocked over. And then slapping it silly fixed it. Huh? It’s weird, to say the least.

Not sure what the cutoff points are between green/yellow and yellow/red, but I usually keep it locked on low for normal use, and moonlight when it’s pitch-black. If I need anything brighter, I kick it up a notch or two, but normally? Low is fine.

Probably why it went from yellow to red then to off so quickly.