Anyone mod their Fenix TK 70? I feel like changing the leds to XML2 for more output and getting a look inside.
Driver Battery contact
Updated : Pictures
Driver top board
Driver bottom board
LEDs on MCPCB
Plastic reflector
After MCPCB was removed Note there was no thermal interface material
MCPCB 18 AWG silicone wires
Back of MCPCB
From what I’ve heard, its a real bear to open it up. Loctite city.
I opened mine up really easy, just put it in the vice and a rubber strap wrench . Wasn’t that hard in my opinion. It has a Triangle MCPCB like the TK75 and also uses a plastic reflector. It didnt even have thermal grease under the mcpcb. I will get pics later
Good work, looking forward for the pics!
Could you also add picture of the rubber strap wrench you used? I don't have this tool yet and sometimes it could be handy.
Awesome. Some pics would definitely be appreciated. I am a little disappointed to find out the reflector is made of plastic. I wasnt expecting that. Either way, I look forward to seeing your results.
OP is updated with pictures
Easily opened the TK70 with 2 strap wrenches and a vice. Reflowed Cree XM-L2 T6 3C leds from Illumination Supply. The copper MCPCB has no dielectric layer under the neutral pad. I measured current between the led and driver
This is with XML2 T6 3C led
Power supply set at 6.13 V
First numbers is the current between driver and led second is the input current to the driver
Turbo : ~2.81A | ~5.6A
High: ~.956A | ~1.5A
Medium: ~0.288A | ~0.4A
Low: ~.018A |
Very nice, thanks for sharing!
The plastic reflectors can be high quality, and in the Fenix lights, they probably are, all depends on the quality of the coating. Reduces weight significantly - Shocker sure would benefit from one... Not familiar with the TK70, but big part of the TK75's benefit is it's light weight.
Nice mod. Was there any thread locking compound on the threads? I dont see any in your pics, unless youve already cleaned it off.
To your eyes, does it appear brighter after the emitter swap?
Its strange that they didnt use any thermal paste.
It appears to be brighter than the older XMLs , its just a bit dimmer than my BTU shocker with the same leds. It had threadlocker but was still not that difficult to disassemble it. Yeah I was surprised it didn’t have any TIM .
Interesting to see inside of TK70. Fenix has been using plastic reflector for many years. To me, that is their strength, not weakness. Surface coating quality is the most important aspect of reflector.
Thanks for the fast reply. Its encouraging to hear that you broke it open, even with threadlocker in place. Nothing like breathing new life into an expensive older light. You’ve got one of the great ones there!
Can you tell us more about which strap wrenches you have? I assume you have 2 and twisted them in opposite directions while using the vice to hold the work in place. I just broke my rubber straps and need to replace them with something professional grade. Darn those glued flashlights! 
Well I couldn’t find my old Craftsman one but I went to Home Depot and saw a New tag on their strap wrenches so I used 2 of those. I actually wrapped one part with a strap wrench and put that in the vice to not damage the finish and get a grip. Then used the other to get the bezel off as that part was tricky. Figure if I break the wrench I can just get it replaced at Home depot .
Great idea using the vice to secure one strap wrench.
Reading your post again, seems the reflector couldnt be removed from the bezel. When you turned the bezel, the reflector didnt get hung up on the emitters? I assume the reflector can turn freely inside the bezel? Just making sure…
Oops forgot to edit that out. I actually somewhat loosened the bezel that let the reflector spin freely. Eventually I got the bezel off that that part. The reflector is held on by those three notches on the head so it doesn’t spin on the emitters
Ah, it all makes sense now. I’ve got someone that wants a tk-70 modded with XM-L2 3C. Given the stories of massive threadlocker overdoes fenix is famous for, I never would have attempted this mod without your post. Ive got a set of mega-strap wrenches on the way. Thanks a bunch for explaining. Given the huge amount of questions pertaining to cracking the tk70, I hope others find yours post.
Cool pics, I opened my TK-70 a few weeks ago and tore it to all hell.Used everything in my repertoire to try to open it including strap wrenches.Thank god it was a non functioning one I bought for a host.It seems to be a brass led board rather than copper in mine,and it fits into the light by way of cutouts in the light body.Good to see someone was able to mod it successfully,nice work 33696933.
DARCANGEL, well thats not good news. Since these are hand assembled, there has been reported a variance in the difficulty in tearing them apart. Maybe yours had clean/degreased threads before the thread locker was applied. Was the host damaged while trying to twist it apart?