Tom,
Thank you for the instruction. Attached are picture of my TR-18. I am still trying to get to the driver. I got my TR-18 from CarpentryHero. I got the driver out following your instruction. Mine did not turn on after putting 3 -cells in.
Picture of the front.
Yes - that's the only configuration I've been using so far, but only used it in short bursts. No problems so far...
kingkong - from your picture of the battery end, the spring pictured there is mounted to the backside of the driver board. There are two tiny holes at the edge of that board - try poking/prying at them with something sharp, stainless steal preferred - mine popped out pretty easily. I have an assortment of tools such as these: dx-stainless-steel-diy-soldering-tools, but have other better stuff too. You could try ss tweezers, but maybe closed to avoid bending the tips. Mine wasn't soldered, but maybe yours is.
Can this current sensing resistor be found and replaced in most lights to up the current, or is it just in these big lights?
I know it's fairly common in these type of drivers, regulated, but don't use 7135's. I believe it can be found in drivers of all sizes. Hannes seems to understand these circuit designs very well but I guess hasn't been replying on this thread. There's been other postings/threads on guys doing the same exact thing to different drivers on smaller lights. Once you find the current sensing resistor, you can tweak it until you get the amps output you want (using a variable resistor pot or other means), then it's set. You can either replace a resistor or add one in parallel/serial, depending on what may be determined.
Ok thanks, that’s good to know. Now to try some light dismantling 
Copying my post here from another J18 thread...
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Got the I-O driver, installed it, wow! just wow! 3 simple modes, easy to install, fits perfect, sandwhiched in the thermal pads it came with between the 2 boards, cutting into pieces to fit. Measurements of the J18:
Before with 3 TF 26650 5000 batteries, as is, not fully charged but in the 4.05v range:
tailcap reading: 3.8A down to 3.1A, fluctuates, usually dropping steady
lumens: 3330 @start, 2940 @30 secs, throw: 34 kcd
After with same batteries as is, not charged in between:
tailcap reading: 5.78A
lumens: 4930 @start, 4726 @30 secs, throw: 48 kcd
Waiting on the TF batteries to charge, takes long on an i4, but should get 5000 lumens.
Wow!
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Tried for kicks, using 3 KK 26650's and got: 6.0A tailcap reading, 5570-4930 lumens, throw: 51 kcd
Beautiful job Tom. That’s an impressive number 
Hello all. Could somebody tell if the leds of this lamp are connected with wires or are they planted on a circuitboard?
In other words, is it possible to rewire them to be connected in series?
Thanks in advance!
Hi Guys,
My TR J18 has suffered the same fate. After about 4 months of use it has dimmed noticeably. I’ve only run 18650’s in it and it’s had a gentle life. Something wrong with that board huh?
I have managed to pop out the driver board but there is that wound copper wire thing on the inside stopping it from coming all the way out out. Doesn’t seem like it will come out without breaking it. Thinking they wired in the driver board first then glued in the reflector? It’s so annoying.
Any ideas?
James
Didn’t understand that wound copper wire thing, mine had nothing else keeping the driver than the power wires. The reflector is not glued, it’s attached with two screws which you can loose from the inside after moving the driver away. The leds are glued to the frame. Silly way since you can’t take out a “drop in”…
Few days ago I figured out that the frame is separateable to two pieces, if one would like to do some additional plotting…
Hey man, did you ever manage to get your driver board out? I am thinking I need a really slender screwdriver to fit past it and release the screws on the reflector… seems like the only way. The driver just doesn’t want to come out of the hole as the coil is fixed to the side of the board anf won’t fit - any help would be greatly appreciated.
I emailed the Trustfire factory and they said “Tks for choose our trustfire flashlight.
Fo tr-j18, i suggest you can repair it by yourself.
You can buy j18 circuit board or j18 led light it.”
So back to drawing board.
Hey
Getting to that point there really shouldn’t be anything holding it anymore besides the pretty tight fitting. I had to pull it so hard that the spring deformed a bit. So just go ahead since you’re gonna swap it anyways?
Yea, I have been pulling pretty hard… 0:) but there’s no way it will fit through. The spring will break off before it comes through the fitting. Thanks for the reply though man.
Hey man,
Managed to get it out after a lot of force, prying and angle. Nothing broke fortunately. Now for the next exciting step of getting a new board and PIMPing this puppy.
Does anybody know if the X-100 can be disassembled in this manner also. I’ve been contemplating on modifying my X-100 too by changing its driver. Is it even necessary or safe to do so?
Driver from lightmalls, designed for 7*T6 in series died today.
I had been using the modded TR-J18 for about 3 weeks until today.
With a dmm I find out there is a shortcut between the positive & the negative input if the driver.
Any idea or suggestion for this problemo?
Zeremefico,
Did you open it and try to find out what happened? Is there any component visually broken? Is it that new version without capacitor or older one with that?
The upgraded driver from lightmalls died, not the stock one.
Yes, i mean that Lightmalls driver. I have also, but with big capacitor. I understood that last ones have been without capacitor?
I have sent it back, waiting for a replacement.
I believe it didn’t have big capacitor, I remember a big terroid wrapped with black heat shrink material.
This driver failure happens often?
It was working with 2 & 3 26650 batteries without any problem until it stopped working. Maybe mine was defective from the start, I had some strange measurements about the voltage output.