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

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.

Problem is, and I think this is what happened to me, is that one cell was “weaker” than the rest. It croked first, then was getting reverse-charged as the other healthier cells kept punching out the electrons. Which is why one was leaking, the other was just starting to leak, but the other two still had some juice left in ’em.

The red/yellow/green stuff presumes all the cells will stay matched alllll the way down to dead, which rarely happens.

What I should do, of course, is as soon as it turns yellow, measure each cell to make sure it’s not gonna pop open like a week-old floater.

That’s what’s more disturbing than anything, I think.

That’s why I’d like to know what’s in/on the driver, whether it could be something that easily gets knocked out of whack.

Sorry, but I had to laff at this. :laughing:

Or GT. :smiling_imp:

slapping and shaking is the answer! :smiley:

This should be stickied. :smiley:

Okay, final resolution…

I had a few days left for the Amazon return-window for the light(s), but figured I’d first ask the nice folks at Thorfire directly if they heard of such an issue, and if so, what was the cause, etc. I much much much would rather have a replacement than a refund, or even just access to, say, the driver board if they had any in stock so that I could repair it on my own. I pointed them to this thread, as well.

At first, it was, “We’re so sorry, they’re discontinued, so we can offer you a refund for both the lights in your order”, but I said the other one is safe’n’sound as far as I know, so only one is at issue. :slight_smile:

Anyway, long story short, they gave me a refund on the one light, and said to not worry about sending it back, keep it, use it in good health, etc. Okay, maybe not in those words, but that’s the gist. (Even though I specified pretty clearly that I seemed to get it working again, via slap-therapy). Also, mentioned that if there’s anything else at issue, not to worry, just contact them and they’ll take care of me.

So, again, pretty amazing customer service from Thorfire!

Time to tear it apart :smiley: and solve the mystery

Actually that sound like they knew the issue. Getting refund too easily in this case.