The Apple Mighty Mouse is maligned by many but I rather like it. I actually replaced one when the track ball stopped working correctly.
Recently the track ball of a Mighty Mouse for another machine stopped scrolling down. The track ball would turn but the window wouldn’t scroll.
Apple’s instructions for cleaning the track ball weren’t effective. But in the Apple Support Discussion Forums in the topic thread “Solution to Dirty Trackball on Mighty Mouse — NO DISASSEMBLY REQUIRED!” is the suggestion to turn the mouse upside down and run the track ball firmly against a clean sheet of white paper. I tried it. There were only a few miniscule flecks of crud that showed up on the paper. But it did the trick. The track ball was restored to full operation.
So with one success, I retrieved the older replaced mouse from the bottom of the wastebasket. This being my home ‘office’ most of the trash is paper and ends up in the recycle bin (sometimes by way of the shredder) and not in the wastebasket. And the wastebasket being under-used and my ‘office’ space being less than spacious, the wastebasket is in an awkward place way under the desk. Which is why a dead mouse would still be in the wastebasket months after being replaced. (Well, that and I’m a bit of a pack-rat.)
I tried the paper technique. A long curlicue of dust-crud emerged from the track ball. The ‘dead’ mouse was resurrected. Thank you LukeAP88.