I tried to document this in hopes that it may help someone looking to do a similar mod to their FW1A Pro.
Shoutout to @INeedMoreLumens for his help and for making the FW3A mod guide.
FW3A T85 to T1616 Upgrade
My main complaint about this light, other than the XHP50.2, is the moon mode is too bright.
Even if you don’t want RGB aux, this is still a very worthwhile upgrade to the 1616 mcu.
I used the FW3A 1616 adapter by adair21, available on Osh.
FW3A T85 to T1616 Adapter
Digikey link to ATtiny1616
ATTINY1616-MNR
Here is the link to thefreeman Aux pcb, but you need to use FLEX pcb.
Hopefully Osh Park starts doing flex again soon. They said they were working on it when I last emailed them.
FW1A_reflector_FLEX_RGB_5050_v1.2
These 0.69mm RGB leds are hard to work with. You need lots of magnification. I use a microscope.
Micro RGB Common Cathode LEDS Digikey : B36S3RGB-F6C0001HOU1930
Do yourself a favor and get one of the Lumintop disassembly tools. It’s only a few bux.
Lumintop SS Unlocking Mu-ti Purpose Tool for FW3A EDC18 HL3A Retaining Ring and Bezel
A lot of these hosts are glued. I used a pair of rubber gloves and heated the front end with a hairdryer which made fairly quick work of getting the head and bezel off.
The mcpcb is extremely thick, so I used farily high heat to desolder the leads. 845f with a large chisel tip.
Here is the driver. You need to remove the T85 mcu and C4 and R4 which are just next to the T85.
I used my hot air station @ 850f and a bit of flux.
Then I cleaned up the PCB with flux and some solder wick.
In the bottom pic you can see the small white dot. Orient that where pin 1 of the T85 was.
I didn’t spot it when I started the mod and was unsure how to orient the adapter.
There is a clear mark for pin 1 of the 1616 in the upper left corner.
Flow your 1616 to the adapter and clean of the excess solder with a small iron. I used a c210 SI tip for cleanup.
At this point, I flashed my firmware. It’s a good way to verify the 1616 is soldered properly. If it isn’t, you’ll most likely get an error.
Afterwards, solder the adapter to the driver pcb.
I used my c210 SI tip. I lined up the adapter, and put some solder paste in one of the cutouts, then heated the pad on the driver side. All the paste will melt and bridge the pads together.
Once you’ve done the first one, verify everything is still aligned, then repeat the process with each of the remaining 7 contact points. It should look something like this when you’re done.
For the RGB wires, I soldered the common/black wire to one of the middle legs of the mosfet.
Red will be closest to pin 1 of the driver board. Green in middle. Blue nearest the 1616 pin 1.
For the emitter I settled on an LHP531 4000k. They have decent tint and can handle some decent current. After desoldering the XHP50.2, I gently cleaned up the factory solder before flowing my emitter on. Sorry, no pics.
RGB board assembled.
Resistor values. Red 30 Ohm. Green 4.7k Ohm. Blue 3k Ohm.
Always test your RGB’s after soldering!
I used 28ga silicone wire for the RGB. It’s a bit fiddly because the flex board will try to lift off of the mcpcb. Sorry, no pics. I’ll try to get some when I take it apart next time.
You need to modify the gasket a little for it to sit properly over the RGB’s.
I did a hasty job with my c210 SI tip and melted little pockets for them to fit. It works fine.
I’ll take more time on my next one.
Now to the meat and potatoes.
Here it is in all it’s glory.
Beamshots locked to these settings.
Hopefully someone finds some of this helpful.
Thanks for reading!
