Robert in CA wrote:
btw I have a logitech m310 mouse and cleaned the lens with
some Windex on a q-tip. It seems to have made a difference.

Thanks,
Robert

Yes, test with a working mouse and see if the
symptoms of mis-behavior go away.

That would tend to support either a cleaning
issue with the defective mouse, or an electrical
issue. And if the mouse cable has an open in it,
you'd probably have a wider variety of symptoms.

The optical part of modern mice is pretty good,
when it comes to dust preventing the lens from
working. The sensor is more of an array than
a single sensor. Don't let the grotty appearance
of the plastics they use for those, deceive.
I know some people, assume the appearance is
a defect, and scrub them, but they don't really
need to be scrubbed particularly. Whoever makes
the sensor assemblies for those, just doesn't
care what the mold plastic looks like :-) Only
if some sort of foreign matter (like the mouse
fell into a bowl of chili), would it need the
real cleaning treatment. But dust does pack
in other places, especially around where the
mouse button cover plastic on top, meets the
microswitch. You can get enough dust impacted,
to prevent the microswitch from depressing.

When you disassemble a mouse for cleaning, be
careful around the scroll wheel. Some scroll
wheels have a tiny bit of a clear gel grease
on them. And you would not want to remove
stuff like that. There are all sorts of
fiddly springs on those scroll wheels. When
you tilt up the hinged cover, do the tilting
in the upright position, so the scroll wheel
doesn't fall out of its mount, onto the desk.
And all those blasted small parts with it.
I learned my lesson when I took my Logitech
apart - what I can't believe, is they design
them with that many parts inside. It must take
a ton of human assemblers to be putting those
together.

Paul