I've searched for a similar phrase about 8 times on Google but never seemed to have much luck (Apple's site isn't very helpful either) so I've decided to create this post so that other Googlers will be able to find this solution to the problem. This is also the reason why I've spelt “scrollball” in two different ways - to catch as many frustrated Mighty Mouse troubleshooters as possible.
I often have had a problem with the downwards scroll on my Mighty Mouse gumming up. To the point that the mouse will register upwards and sideways scrolls but not downwards (there's no telltale piezoelectric click either).
Apple's suggested cleaning methods aren't too clear.
The first one, vigorously rolling the mouse upside down against fabric works reasonably well for small scale blockages, but over time a larger one can develop.
Here's where Apple's second suggestion needs to be expanded upon. It says you have to dab the scroll ball with a damp cloth.
The way to fix the blockage is actually to slowly scroll the ball, bit by bit with a damp cloth, the moisture binds together any surface grime and dust into chunks of detritus which are easy to remove, eventually, enough water gets into the main blockage to let it be dragged out with the scrollball for easy removal. However, make sure the cloth is wrung out such that you don't get much more than a tiny skin of water on the scrollball - the last thing you need is to introduce water to the Mighty Mouse's innards (for very obvious reasons). The whole process should only take a few minutes and you should see some results after the first few scrolls.
Viola! One clean, fully functioning Mighty Mouse! Enjoy.
Later
John
Posted by John Swaine at October 29, 2005 02:56 PM