Chosen Solution
I took my MX Master 2S apart from cleaning and everything went well. Sadly a new issue arose when putting it back together. When i attach the cable for the side scrollwheel/button, the sensor stops working - the mouse no longer moves on the screen.
The mouse works perfectly without this cable attached, but i sadly loose the ability to use the side scrollwheel that way.
Has somebody else experienced this issue aswell?
So after all, the gesture button (where your thumb rests on) was constantly pressing the gesture function of the mouse, deactivating mouse movement. Looking further into the “constantly pressing Gesture Button” issue, i found out that it seems to be a quite common defect. While some people seem to just cut of the button entirely, you can also deactivate the Gesture function completely in the Logitech options software. Turning the Gesture Button PCB around fixes the issue completely and retains functionality, i found it out by trial and error. I hope this can help someone else in the future aswell, the plastic mechanism holding the rubber away from the button seems to weaken over the years. Anyways, thanks for the help, iFixit is the best :)
if u plug the ribbon cable back in and then the sensor stops working, that sounds like a ground somewhere. check both ends of the cable. make sure the pins are good and not bent or broken on it. also look around the components on the board for any burnt\scorched spots. what did you clean it with? did u let it dry (if something wet was used) before powering it back up? better yet did u remove the power source from it?
Had exactly the same issue here (optical sensor stopped working out of nowhere). It turned out that the “thumb button” was screwed in a little to tight and started triggering the “gesture” command through the software the whole time, deactivating the optical sensor. I disassembled the mouse and untightened a bit the “thumb button”. Problem solved. :)
