Anyone Successfully Mod a Fenix TK41 or TK60?

EDIT: Now Im looking to swap LEDs in the TK41 / TK60 assembly. See my last post on the 2nd page.

I did my first mods last week, a neutral XPG-R5 to a Rayovac Sportsman Xtreme Lantern, and then a neutral XPG-R5 to a PrincetonTec EOS headlamp.
I am a little happier with the neutral white color. I don't like warm but I think neutral white is the right balance.

Now that I have the modding bug I'm looking at my Fenix lights. My LD20s are a little too cool white for my taste, especially since the LEDs aren't driven that hard (which would seem to produce more "white" color). I have a TK40 that has been sitting around for some time now, and am looking at a used TK45 at a good price.

I have heard that Fenix uses thread lock sometimes, and I can't figure out how to even get the heads apart for my TK40 and LD20s. Has anyone ever succesfully made mods changing out the LEDs for these lights?

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

If you look closely at the LD20's head just above the hex you will see the line where the head is threaded together. I haven't modded one but imagine it to be vrey similar to a Quark which I've done several easily.

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

think2x said:

If you look closely at the LD20's head just above the hex you will see the line where the head is threaded together. I haven't modded one but imagine it to be vrey similar to a Quark which I've done several easily.

Click to expand...

I just took a look and there is no hex at all. No holes or anything for support the screw the LED / PCB portion out of the head either. I don't know how the got the thing assembled?

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?




I did this really quick. The arrow is pointing at the spot where the head joins together just below the lettering on the head and just above the anti-roll (hex) on the bottom of the head. Follow the steps I did here......http://www.candlepowerforums.com/vb/showthread.php?329841-SWM-V10A-HCRI-mod to open the head. Heat may be needed but probably not.

Let us know how it goes.

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

Excellent! I'll give it a shot when I get home. Hopefully the stock XPGs are on a 16mm wafer like the neutral XPG-R5s I can get. That would make the swap easier.

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

Reflow soldering isn't all that hard to do, it just takes a little practice and patience. Most likely the board the neutral will come on will be thicker than the fenix board and if used will cause the head to have a gap when put back together if.

Feel free to PM me if you need any advice/help.

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

I want to keep this thread going instead of just PMing with questions, just in case anyone else is eager to try and is stuck on what to do next.

I did something like the method you described in the thread above. I could not find any rubber or anything to use between the flashlight head and the wrench, so I actually wrapped the top of the head, and then the "bolt" like portion in the picture above (with the 8 or so flat surfaces) in about 8 layers of electrical tape each. Then I put the bottom "bolt" like portion into a vice that is bolted to a workbench, and the top of the head I used with the wrench. With a lot of pressure, I finally got the top head portion to unscrew. Fenix actually used blue locktite, not red.

The LED is on a small PCB. It looks almost exactly like the white PCB in the link you provide, only a little smaller and the holes instead of closed are open (the two). There is a black plastic piece that actually fits perfectly over the square LED iteself (there is a square in the black plastic piece) and has two black pegs on each side that slide into the holes on the PCB. So I'm assuming when Fenix makes these lights this is how they make sure the LED is centered. The postive and negative wires are obviously soldered onto the PCB, but I don't know how much play I have with the wires. The PCB is epoxied to the flat metal part of the head (and not tightly, I got the PCB loose) but I don't know if that flat metal part actually comes off. I tried to pry it off (there is a screw and another solder point next to it) and i unscrewed the screw. But it didn't seem to do anything.

So it's obvious the netural LED itself will have to change PCBs and go to the smaller white Fenix one. My question now is how do the positive and negative work out with the square LED on the tiny green PCB? In your link you heat up both whitish PCB and darker one to get the LEDs and their green tiny PCBs attached to them off and then swapped, and then heated up again. But how does the postive and negative work? Does the little green square with the LED attached to it matter on how it's placed on the PCB? I noticed that two corners of the little green PCB are two white squares. The other side are two darker squares. I thought one the whites must be on the same side as one polarity and the darker squares must be on the same side as the other polarity. But then I looked at my other neutral white XPG and the square colors are reversed on sides of polarity.

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?




The red line in the picture is positive. If you look at the "green square" and have the 2 dots in the BOTTOM 2 corners, the right side is the positive side. You will understand easier after you get an emitter off the board.
It sounds like Fenix is very similar to the way Jetbeam does their lights with the two "legs" on the emitter centering piece.(whatever it's called) If it is like the Jetbeam then it's only thermal paste and not epoxy, the alignment piece and the reflector hold the emitter in place and the thermal paste transfers heat. The additional solder point you spoke of is the "head loose" negative input. This is the way a Quark is also done. when reflowing, don't leave it on the heat too long, only long enough to make the solder molten and remove the emitter.

I'll check back tomorrow and see how it's going.

Jamie

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

The wires are so short that I don't think I'd be able to get the board back on once taken off. The postive and negative wires would definately retreat into the holes as soon as I desolder them, and I wouldn't be able to get them back out. I'll bet that what Fenix did was take longer wires and cut them right before soldering them into place, hence the really short wires. Can I just put a blob of solder real quickly under the LED onto the center of the stock board? My main goal would be to install the LED without removing the stock board. Can I use my thermal past instead of solder?

Does it matter if when soldering the LED square onto the boad, if I do a line or a dot of solder (in the middle) under the LED onto the board?

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

When I reflow solder I don't add anything between the emitter and board, the solder that is already there is plenty to do the job. The wires on the Quark lights sound VERY similar to the Fenix, they are very short. The Jetbeam look short but after desoldered can be pulled out of the hole quite a bit with tweezers. The Fenix driver is probably pressed in tight like the Quark, I haven't gotten a Quark board out and been able to save it yet.
If you desolder the emitter wires I don't think they will pull under and disappear. I think at the factory the driver was pressed in with the wires fed through the holes and then the wires were cut and soldered on.

Can you get a picture of the the head opened up showing the emitter side revealed? It would help me if I could see what you see, I've only done Quark, Sunwayman, NovaTac and Jetbeam but they are all very similar with little variances.

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

Darn, I guess there's no attaching images directly? I don't have any webspace anywhere. Could I email you the pictures or something?

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

PM sent with image hosting suggestions and E-mail address. If you choose to E-mail I will post them here so we can all see for future use.

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

Email sent with the two pics think2x. Thanks for the help.

I got the LED itself off the PCB. I have a plan to get the neutral white on the already installed PCB. I'm going to heat up the neutral white LED already installed on the PCB from the store. Then I'll take the LED itself off when the PCB gets hot enough. I'm going to essentially put tape over the black pastic holder on the PCB already, and cut a hole in the center of the tape. This will make the black plastic holder snug against the flashlight so it doesn't move. I'm going to put my LD20 in a vice facing up so it doesn't move. Then with the LED in tweasers in one hand (maybe I'll have my dad help out by doing the solder, or I'll solder a drip real quick onto the center of the PCB and he'll quickly place the LED in the square of the black center piece. He'll apply very little force on a corner or something of the green square part of the LED (not the round LED itself of course) and it should dry in seconds. THen I'll epoxy the installed PCB back to the head of the flashlight. It's harder to mess up the LED install so I want to do that first, and just in case if it's a little off center, I can slightly compromise that by the install of the PCB.

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

Here ya go, Fenix LD20 exposed.

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

You really need to reflow the emitter back on the board. The wires on the Quark lights are that short. They wont pull into the head if you desolder them and use tweezers to move them over. Follow the method I used in my thread with the reflowing and it's pretty easy.

You don't need anything additional between the emitter and the board, the solder that's there is enough. Too much will most likely bridge the pads and create a short.

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

Hmm what do you mean by bridge the pads? In the picture above the bottom thin line is the (+) and the top thin line is the (-)? And if there is a solder in the middle that will touch both ends, the LED will short?

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

The two thin lines are the positive and negative, the center pad is for thermal transfer and is also either a positive OR negative (I don't know which as I haven't researched it yet)
Have you heated the other emitter board up to remove the neutral emitter from it yet? Reflowing it is the only real solution at this point, I don't think you will be able to achieve satisfactory results any other way. Besides, all you need is a steady hand and a heat source.

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

I have one of those newer electric stove types without the coils. I guess it should still work on getting the LED I want off its PCB. Is there any other device you can think of that might work to warm up the LED PCB so I can get the LED off? The LEDs should be in the mail tomorrow or tuesday BTW so I don't have them in front of me yet.

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

Soldering iron under the board while being held in a "helping hands" type holder.

A Cast iron skillet may work on top of the stove and hold the board on the lip of it.

Heat gun under the board may work but may also blow the loose emitter around a cause more trouble than help.

If I can think of anything else I will add it.

Re: Anyone Successfully Mod a Fenix LD20, TK40, or TK45?

Small update.

I did a reflow with the "helping hands" and soldering iron today on the thinner Sunwayman copper XM-L board and it worked good but wasn't enough heat for the thicker (2mm) 10mm diameter boards from Illumination Supply so I had to use the stove eye again.

I did a little reflow video but need to change it's format so imageshack will let me upload it.