i had a problem with the slider switch twice.

i took the switch out, opened it up and the 2 little foil contacts float insode the switch. they had gotten messed up and needed repositioning. after that, no problemo. but it happened again after a month. same thing, fixed. we’ll see how long this lasts. might just need to buy a new switch and solder it in next time. mines under warranty, but i forgot to register and blah blah blah

just throwing it out there. helped me with similiar problems.