Solution to QC35 won't turn OFF or Turns ON by itself
Let me share the ACTUAL FIX for most 'magically turning on' or not actually turning off' issue.
This is due to the switch being too early in the slide to turn on and the aluminum cup nudging it towards that point where device turns ON.
What you can do is:
1. Remove the ear cushion and the 'R' cloth cover.
2. Loosen the 3 screws holding the metal cup. No need to remove.
3. Without removing the cup, face the cup and push it the left on its place.
4. While keeping the pressure to the left, tighten the screws. (DO NOT over tighten. Just enough to allow a gap on the left side of the switch and the cup be secured..
The cup may have deformed or even moved towards its lifetime + slightly loose screws. The deformation of the cup or some movement slightly nudges the switch to the ON position which the switch is very sensitive due to possible wear pattern for that switch.
I fixed mined and it's not magically turning on anymore or not magically turning off.
*warranty may be VOID by doing this*