Have an older Fenix TK70 with problem

LED Flashlights – General Info Other Battery Type Flashlights
1

I seldom use this flashlight (Fenix TK70 - running 4 Tenergy Ni-MH rechargeables)… probably 6 months ago last time… worked fine then. I store it without batteries engaged. Now it will not stay on… hit ther button… only “flashes on” as button is being released. Not on the way down… just the way up on the button. Mode button does nothing. Have switched batteries… no change in behavior.

Any of the light experts here tell me what’s going on? And if it’s worth even trying to fix? I’m well aware there are lots of lighter / brighter / better flashlights out there now… but IF it’s not a huge problem to fix … it was the most expensive flashlight I ever paid for (it was something in it’s day I suppose)…

Thanks!!!

2

First thing I would do is try new set of batteries. The batteries you have may have an internal short
And yes… they may still work in other devices. I would try regular Duracell D batteries as a test.

Worth a try.

BTW, that light was top of the line when it came out. Very cool light.

1 Thank
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thanks for the reply… yes… i have tried other batteries… no change.

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Doh! You were correct! I had switched out the batteries for my backup set of Ni-MH batteries… and got the exact same results… figuring the batteries weren’t the problem… wrong. i stuck in some brand new duracells… and it worked! Then I voltage checked the Ni-MH batteries… and had a bad one in each set! Thank You for the help!

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Glad it worked out, that light is a keeper.

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After clean as best as you can all the contact parts and a new sets of battery, I presume the problem is the driver.
What battery it use?

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I have one also, it is a Fenix TK70 and I think of it as the pinnacle of the D light era.

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That was great advice. Ive also ran across aged NiMH cells with intermittent internal shorts. Its seems to be exacerbated by the high spring pressures used in some battery tubes.

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I still own a TK70 and reflowed some new emitters to wake it up a bit. They dont make boost driver like that any more and the TK70 came with one of the best I have ever seen. It was offered in other markets with 2 x 32650 cells and a shorter battery tube to accommodate those cells. After some research, I discovered both versions shared the same driver, so now I use mine with 2 x 32650 unprotected cells (8.4V total) and a D cell maglite tail spring with wire mod to take up the slack. Its far lighter and shorter in that configuration and powers the light slightly longer than when using 4 x D NiMH cells.

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curious to hear more details of that… Did you just use the tube without the extension (3 size D cells)? Or a separate tube altogether? Are You using Lithium batteries? How does 2 8200 MaH batteries outlast 4 10,000 MaH Ni-MH (voltage difference do that??)…