Odd Mouse Wheel Problem

[Frank Jahnke]

On Fri, 2006-08-04 at 16:16 -0700, Joe Kelsey wrote:

> The MX700 uses buttons 6 and 7 to scroll up and down.  I remap the
> buttons on the moused command line:
> 
> moused -m 4=6 -m 6=4 -m 5=7 -m 7=5
> 

The answer turned out to be quite different: cat hair.  The scroll wheel
was packed full of cat hair.  I'm amazed it worked at all.

That it was not the mapping became obvious when I used xev, an X program
that displays mouse clicks and a whole lot more information.  Nine of
the 10 buttons responded well when they were pressed or moved; the only
one that did not was the scroll wheel that would move up a page. It was
pretty clear to me that either it had failed electrically, or that there
was something else wrong with it.

I took the mouse apart, and found loads of cat hair forced into the
wheel, which is slotted.  There is a transmitter on one side of the
slots and a receiver on the other; undoubtedly there is a pulse counter
that records the number of clicks.  

Apparently the scrolling direction moved the mass of cat hair enough
that it worked in one direction but not the other.  It took me two tries
to get it all, but now it works flawlessly.

It seems that my comment about the differing response when X11 was set
to different modes was a red herring.  The hair must just have moved
differently when I tried that.  Who knows.

Frank