So for my one-button saber, the button started acting wonky, to the point that it was very rarely working.
It can still power on/off with twist-on/twist-off effect, getting sound and lights. I assumed the switch (chassis button) was broken, so I bought a replacement and wired in the new one. Still have the same problem; for the most part it’s not working but on rare occasions it does trigger it on. Right when i first wired it in, it was working and i was turning on/off + cycling through menu etc. then it stopped working. I’ve tested for wire continuity with multimeter and I’m getting the beep when I check the wires connecting the switch to the board.
Thoughts/Suggestions? Thanks in advance.
Have you checked continuity from GND to BTN1 on the board, and then press/release the button to see if you get beeps when you push the button?
I have continuity between the GND and the Batt- but not BTN1…
For additional reference, I have my button wired to BTN1 and Batt- on the opposite side.
Edit: also for additional reference, the button just turned the saber on a moment ago as of the time I’m writing this
Could try some contact cleaner or IPA in the mechanism to see if that helps.
GND and Batt- are connected inside the board, so it makes sense for them to have continuity.
You should have continuity betwen BTN1 ↔ GND/Batt- when the button is pressed, if you do not, then there is something wrong, either with the button or the wiring between the board and the button.
Well of course soon after I resort to starting the topic here, the saber seems to be functioning fine now. It for sure wasn’t for about a week before I replaced the switch, and even a little afterward it didn’t seem to be functioning. Who knows if replacing the switch even had anything to do with it? 
So I’ll remain cautiously optimistic for now, but with my luck it’ll stop working again soon after I post this 