What I suspect is that it was some sort of surface protection for the copper PCB and it was supposed to be peeled off prior to instalation, it is like the very thin kind of tape the factory puts on the back of new watches and the user has to peel it off before use.
When I first removed the led PCB the copper back looked the same color as the copper wire used in transformers, that is what gave it away, then when cleaning it to remove the white thermal grease, it started to peel off.
I was able to source an extra stock TN-31 copper PCB from another member who moded his light, when it arrives will check the back for the presence of the tape and post pics if its there.
wow thanks for the how-to! just wondering which SMD resistor that one is. unfortunately i don’t have a pic of the tn31 so i just stole turbobb’s k40 pic, i hope he doesn’t mind. is this the one? i hope tn31 has a similar pcb
Yes that is exactly the one, you just solder another smd resistor over it and the current will increase, BTW while you are soldering an extra resistor you can also upgrade the base of that spring with more solder.
oh btw don’t use Flitz on any thermal interface. it gets into the pores of the metal and inhibits thermal transfer. instead use thermal grease to polish the surfaces. doing this impregnates the metal with conductive particles
i learned that the hard way when i was working on a watercooled 172-Watt thermoelectric cooler
The resistor mod does not alter the other levels as far as I can tell, only the highest level is what gets boosted.
The digikey part number for the 1206 0.082 ohm SMD resistor I used is P.082AVCT-ND,
Thanks for the tip OC, I did clean both parts with alcohol before using AS5, and I know the results are better than what came from the manufacturer, I can tell right away the led module heating up fast when in use, so the thermal transfer must be working as planned.
Alex,this is a great tutorial thanks for sharing.I will eventually do this mod when I have time.Can a 20mm sinkpad be used instead of the factory board?I assume it's smaller than the factory board but would it be a disadvantage to do so?
I have done these mods to my supbeam but now it has problems.
It only lights up on mode 1 & 2, all levels past just stay at m2.
even the strobe. standby turns the light off. But wen it is all together the
Tailswitch does nothing. The light just stays on. I hope this makes sense
And that someone knows how to fix this prob.