I tried bypassing the tailcap and it still just steps down through every mode until it is off.
Is it possible to reprogram the driver?
Thank you, I was looking for a way to reflash the driver though.
Well, try to see if you can get it into programming mode and see if you can set the modes back.
If not, you could buy a preflashed MCU from Mountain Electronics for $1.30 and reflow it onto the driver, but that might not solve anything.
If it were me, I would just replace the driver with a MTN FET+7135 with Bistro firmware and be done with it. I know you paid good money for the light, and could ask Banggood to replace the driver, but that could take months of haggling and waiting, and you could end up with another driver that encounters the same problems. The MTN FET drivers are solid and you could get it in a few days.
Guess I might as well post this here. Finally decided what I wanted to do with my “1st gen” S41 without the glue (are they still gluing them?).
I decided to go with a mixed tint high CRI XP-G3 setup.
2x 5700k 90+ CRI
2x 3000k 80+ CRI
The outcome is quite nice, Very nice white tint with GREAT color representation. Reds and blues both pop but not artificially. Very natural light and very high CRI from my eye balls perspective.
Can’t wait till tonight when I can try it outside. It ended up around ~4500k I would say (makes sense, the math says it should end up there).
It does have a bit of tint shift around the edges of the beam but nothing horrible IMHO, at least when not white wall hunting.
That is until I mistakenly dedomed one of the 3000k lol. It had a spec on it and while trying to clean it off I took the dome with it, now it has a slight ring around the outside. I will fix it when I swap the driver for a Texas Avenger down the road.
Oh yeah, it pulls around 17 amps and puts out over 3000 lumens before the dedome.
Overall I REALLY like it so far. Can’t wait to try it out in the morning.
Great idea T-A
I just ordered two of the new S41S. One SS and the other rainbow SS. That means I’ll be looking to use my original unglued S41 for modding. Still not sure what I want to do, but thanks for build idea.
Yeah, it easily puts my 219C triple to shame (interesting it also has a smaller hot spot). The S41 gives of a VERY natural light and colors look natural. The 219c gives a good tint but colors are muted by comparison.
The plus for the 219’s is that they don’t have the tint shift issue but that doesn’t bother me in the real world.
T A
Where did you buy Nichia 219C?
I’m looking to upgrade mine also
RMM sells them: Nichia
I am using the 80cri 280 bin in the triple right now but I have some of the 320 bin 70CRI as well, just not actually used them yet.
I got to use the S41 mixed tint light this morning and in a word WOW.
I have to say that I am really impressed with the combo. It is a hard pick between it and the BLF-348 219B for best overall tint and color rendition.
The S41 is a bit warmer and due to the dedome it is hard to know exactly what it would look like normally. This is only noticed when white wall hunting, in the real world colors are so crisp and clear along with a great tint. Everything looks just like you would expect, not color shift outside. Without the dedome I am sure it would be a little better as well.
The BLF-348 is a bit more “white white” and colors pop quite good as well, just not quite the same. It is more pleasing to the eye on a white wall due to the pure white tint but when actually looking at something I prefer the S41, it is just easier on the eyes.
The S41 can obviously be much brighter as well which is nice.
Overall the real difference is mostly in the midrange colors, A good way to compare tint and CRI is to shine one light at something then shine the other light at a simular brightness “overtop” the first beam and see what colors suddenly look better. Then reverse the process.
For example the greens and yellows show up a lot better with the S41, red also looks a bit better as well. Even blue looks a bit better. In fact there are more of all the colors really, just some less noticeable then others.
It needs a Texas Avenger driver for sure though, with the stock driver it gets HOT fast with no regulated modes, like sear your flesh hot in 30-45 seconds on high. Great fun but not super useful, a regulated Texas Avenger driver should work out great and net something like ~800 lumens in the regulated modes.
If anyone wants to copy this there is a great deal on the LED’s I used right now.
90+cri 5700k XP-G3, great cool white LED, my favorite cool white LED I have ever used to be honest. https://www.arrow.com/en/products/xpgdwt-u1-0000-00fe2/cree
80+CRI 3000k, not bad by itself but warm for sure: https://www.arrow.com/en/products/xpgdwt-h1-0000-00h7e/cree
same specs but slightly different tint bin, I honestly have no idea what the difference in the bins are but I used one of both: https://www.arrow.com/en/products/xpgdwt-h1-0000-00he7/cree
Arrow has free shipping this month so it is a heck of a deal indeed!
If you need any other components grab them while you are at it, the fewer shipments they have to make the less money they loose and the better the chance they keep free shipping around.
For example Attiny85’s are less then $1 each and they have tons of other components as well.
thanks T A
That’s alot of good info 
will mod mine soon
Ordered 11 of the 90+cri 5700k XP-G3, 2 quads and a triple, thanks for the heads up!! 
:+1:
Rats. They have XHP35-HI 57k 90CRI, but have to order 1000.
Where’s your commitment?
For a cool white emitter it is great but it is cool white indeed. for those setups I would highly recommend mixing in some of the 3000k. It really balances out the tint and CRI.
Yes, if you remove the driver to access its top side, the MCU should be accessible and can be reflashed with about $20 worth of extra equipment. But I doubt it would fix the issue with it always stepping down and shutting off; that usually indicates a hardware problem.
So I’d start by touching each solder joint for a moment, just long enough to melt it, to make sure nothing is cracked or loose. Then check if the issue still happens.
I’m using a nitecore IMR 18350 7A 3.7V battery. I noticed the battery check doesn’t work like on the specs. For example, mine blinks 4 times when 100 percent, 3 times between 75 percent and 100 percent, 2 times when between 25 percent and 75 percent, and one time when below 25 percent. Is there a different 18350 battery I should use? Or is there a problem with my firmware or something else?
Here are some dirty comparison shots between various 90+ CRI lights. The white balance was corrected to neutral for each light to keep things fair from a CRI standpoint.
First up the mixed tint S41 with the accidental de-dome:
Here is a 3000K XP-L 90+ CRI, note that the contract around the edges looks better on this ligt but it is deceiving due to the hotspot being concentrated to the bottom left corner of the picture and not an even spread like the S41.
Lastly here is the 5700K XP-G3 by itself, same problem as the XP-L in the tighter hotspot gives the appearance of more contrast on the outside edge.
Overall you will see that the 5700k is surprising for a cool LED but still doesn’t bring out the reds and warmer colors as well. The 3000K brings out the warmer colors a bit too well honestly but still looks good at first glance. The mixed tint S41 has a great combo of both worlds with a very even and neutral color rendition.
Do we have the mouseover image option on this site or was that a CPF thing? Never used it myself.
No idea, but I think you need a 2017 calendar that’s a bit more manly TA. :innocent:
Real men wear Lisa Frank.
Or it could have been the most colorful thing I could find with which to take comparison shots with.
Who cares, I am not ashamed either way. :disguised_face: