Ok, here are measurements just retaken for the inductor side, clockwise again starting top left with the inductor to the right hand side of the chip.
1.4, 0.03, 0.03, 0.03, 3.8, 3.8
Oddly, this matches my ‘anomalous’ set of readings from yesterday for this chip…
… and after a break and re-measure I get exactly the same again.
Switching gears. Unfortunately I’m not sure what these measurements indicate. No slam dunk 
So new strategy, more annoying for everyone I’m sure. Let’s use the ohms mode on your meter and check a few things…
Sorry, but you’ll have to give me another walkthrough.
Should the LED be on, and if so in what mode? What do I need to touch both wires to, and what range should I set the DMM to?
You don’t need the LED in the circuit. Set your meter to 2000 Ohms. Stick the probes on the points in question and insure that it reads zero. EDIT: or that it reads one. If it reads something else then that means something too but is probably less useful.
I started drawing a circuit diagram but it’s still got more stuff missing than present 
Should it still work with the LED in the circuit? I’ve just testing with it all still intact but with no cell.
LED- (attachment point of wire to circuit which goes to LED- input) to ground (driver negative contact) gave a reading of 091.
LED+ (attachment point of wire to circuit which goes to LED+ input) to the small gold pad between the 2R2 labelled inductor coil and the adjacent little brown box with silver ends (assume capacitor) gave a reading of 007. (To be honest I wasn’t sure where exactly you meant for this one so I made a best guess, please let me know if incorrect).
Having the LED in circuit is not a problem.
The FET / transistor is marked “2300”. Please use whatever methods are necessary to determine what the the thing is hooked up to. We can clearly see the connection to the pin next to the zeros. I would like to know where the middle pin and the pin next to the “2” connect.
Ok, the pin under the 2 goes on a short trace underneath the tiny black component marked ‘EB1’ below it (I’m not sure if it actually connects here of is insulated underneath the surface) before going through to the other side to meet ‘pin 1’ of the unmarked ‘SOT23-6’.
The middle pin on the other side goes no-where on the same side of the board, and appears to go through directly to the -ve output to the LED. Would that make sense?
Here's a rotated/aligned/resized version showing both sides (sorry for the 1200px table breaker, deal with it :p )
Use as a reference for whatever you guys are doing, I don't want to ask my own set of questions at the same time, that's like trying to diagnose something using alternating steps from two different manuals, doing that never turns out well. :sick:
183 represents a 18 followed by 3 zeros, or 18,000 OhmsEDIT: Good work comfychair, thanks. I was being stubborn and just using the pictures the way they were. It was costing me a lot of effort.
Thanks for doing the images comfychair, I was sort of hoping someone would do that so I could understand what was going on a bit better (and sorry for the crappy originals)
2. My DMM does support this assertion, if you mean 0 Ohms resistance between that middle pin and LED -ve. Oh dear…
Comfy’s got the cathode of the diode marked with 5, and LED+ marked with 5. That’s what I’ve been assuming as well. I would now like to know where the anode is connected. Is it what comfy has labeled 4?
I think the anode goes to ‘pin 6’ of the SOT23-6 on the inductor side via the capacitor near it (bear in mind this is top right of comfychair’s pic as I made readings with the inductor coil to the right of the board).
I’m not sure the cathode goes to LED+ tbh (in fact it looks more likely that the anode does to me), though it certainly goes to ‘pin 2’ of the CFC3W chip. I could very well be wrong though.
In the R/H pic, there's two vias one above the other, nearly dead center of the board... follow that to the other side (remember, the two pics aren't mirrored to make left left and right right so the R/H side of the R/H pic is the L/H side of the L/H pic - confused now?), near dead center of the board would put those two vias under one pad of the big diode. Looks like the other end of the big diode goes to the top pad of the inductor. That would make sense since a boost converter acts as a pump with a one-way check valve.
Is the LED- wire connected to something on the battery side of the board? I can't tell if there's a via there or if it only goes to the SOT-23-6 on the topside. That's something to track down with the ohmmeter.
I'd also like to know what the pins on the FET connect with. I'm still not clear just going by the pics if it's a N or P-channel. Voltage on the gate pin in all the modes would be interesting to see too. If it's a N-channel, and it's no higher than battery voltage in high mode, then you're back to the solution of jumpering B+ onto the gate and you get a single mode light (and removing whichever of the SOT-23-6 chips isn't the boost controller).
B+ to gate will prevent boosting. [edit: unless I’m missing some fundamental thing?] I think we’re on the same page about the rest, assuming you mean the pad you marked “4” in white.
EDIT: for clarification, a boost converter needs to generate a voltage spike from the inductor, so it’s got turn the FET on and off to do that. Connecting the gate to either B+ or ground will “stick” the FET either on or off, no more switching. The gate pin may be pulled high or low with a resistor, but it can’t be wired directly to either B+ or GND.
I think you’re about right with the connections on the big two connection chip, I described my own observations about it’s connections in my last post.
Yeah, that’s what I just checked for wight. The LED- wire seems to be connected through the board to the top middle pin of the chip marked 2300 on the battery side. This is backed up by readings of 0 Ohms between these points (I think that’s how it works anyway).
Which one is the FET, and which is the gate pin?
Or is this possible solution unfeasible as wight pointed out?
Unfeasible, at least that method. I think the goal you guys are working towards is to find which pin on the MCU is controlling which pin on the boost converter to give the different modes, and then jumper whatever between those two ICs to make it high mode all the time. Oh, and also which of the two ICs is which. Stick with the flowchart in wight's service manual, ignore my ramblings unless/until he says otherwise. :p
The FET is marked '2300', orient it with the single pin at top and the two pins at the bottom - the top pin will be drain, lower right the source, lower left the gate. Switching voltage on/off to the gate connects/disconnects the source & drain pins (it's like a relay but with no moving parts). (unless it's a P-channel FET, which means all that will be backwards)
Ok, I have some new information which may or may not be of use.
Whilst re-centering a Nichia 219 that I run direct drive in an old Thrunite Saber 1A I noticed that the original circuit made use of a 6-pin chip identical to the one on the B+ side of the DQG light and marked ‘CFC2S’. As the Saber 1A uses a boost circuit but current control instead of PWM it suggests to me that the ‘CFC3W’ chip may be boost related rather than controlling modes. Does that sound a reasonable inference?
More or less. CFC is probably an identifier (arbitrary, manufacturer specific) and the last 2 characters are probably a date or batch code. So they are likely the same chip. Unfortunately we are still unsure as to how PWM modes are implemented. I can think of a couple of weird ways they could be done. Based on your work so far, it appears that the FET is controlled by the unmarked SOT23-6, so I’d say that some weird way or another is employed here.
I should update my schematic a little more, haven’t updated it with everything we know yet.
Is there any update on your circuit diagram?
Do you think I should try some more trial and error bridging on the inductor side chip to see what happens? If so do you have any recommendations as to where may be the best place to start?