Fenix TK35 Rattle Silencer...

Hello fine people. I got the Tk35 and like it except for the rattle. I opened up the switch mechanism and placed a tiny piece of closed cell foam, about the size of a bb, inside the rubber switch covers and put everything back together. It worked and there is absolutely no rattle and the switches aren't affected by the tiny bit of foam. It was an easy 5-minute mod. I used a bit of foam from an exercise mat but I think anything resilient will work. Someone suggested petroleum jelly. That would probably work too but it might leak.

I did the same thing to my LD40. I used felt sticky pads, (like the ones for furniture.) I trimmed them a bit, and stuck them on both sides of the battery carrier, and stuck a tiny piece on the switch as well... = ZERO RATTLES!

you're almost there. But for one thing, using petroleum jelly will eventually destroy the rubber switch cover. since you did already open up the switch mechanism, the one that rattles is the plastic protrusion for the mode switch, what you could do is to put a tiny piece of paper in between that plastic and the rubber cover so the rubber cover holds it down from moving essentially what you are trying to do is to remove the slack between the rubber outer cover and the plastic protrusion that pushes the mode button. For the power button, for good measure, i cut out tiny pieces of post-it(the part with the adhesive) and stuck it on the power switch. Voila! rattle fixed!