The scroll wheel of my Mighty Mouse often stops scrolling down although it will continue to scroll up and side-to-side. I have followed the directions in How To Clean Your Mighty Mouse and they have always worked in the past. This time, no go. I used a slightly damp cloth, turned the mouse upside down, and moved the scroll wheel in all directions (lightly, vigorously and with and without pressure). This has always worked in the past but not this time.

Any suggestions?

When that same thing happened to mine, I could click and hold it and scroll down and it would work. Doing that a few times cleared it out and it starts working again. Also try changing USB ports temporarily.

Thanks for the suggestions but they didn't work. To add some info to all this, the scroll wheel sounds different when scrolling down as compared to scrolling in other directions. It also feels different although I'm sure that it is rotating.

EDIT: The wheel may not actually be moving when scrolling down. Sometimes it feels like it is and sometimes not. The sound is definitely not right.

For some reason it is usually the scrolling down that gets sticky on my MM. Sometimes it chatters as if there were a slipping gear inside.

I have sometimes found the build up of body oils and dust in the scroll ball needs a bit stronger cleaning solution than that recommended by Apple. Placing a household cleaning wipe on a semi-soft surface, like a soft mousepad and then turning the MM upside down and thoroughly scrubbing the ball across the cleaning wipe in every possible direction several times has always cleared it for me. Good luck!

Sounds like a good idea, joe, but what exactly do you mean by a "household cleaning wipe"? As you can see, my normal domestic chores (or lack thereof) have not enlightened me about such things.

There are several brands on the market but Clorox is probably the most widely distributed. They come in a paper/plastic tube and are marked something like "household surface wipes". They are disposable towelettes pre-moistened generally with alcohol related compounds that are very good at cutting grease and oils. Some are scented with orange or lime oil which supposedly enhances the ability to cut grease and oils.

I tried your suggestion using rubbing alcohol instead of water and it didn't work. I will phone Apple (I still have Applecare) for alternative ideas and also to see if Apple will replace the mouse under warranty. If they suggest that I take it to a Genius bar, I'll try that. Worst case: I'll buy another mouse.

UPDATE: It's working now. I had left the house for a few hours and then tried the mouse again. My guess is that enough alcohol got into the mouse's innards to dissolve the gunk that was interfering with scrolling but it took a bit of time. As I write this, scrolling seems normal.

My bad

I forgot to mention that you need to allow time for the solvent, alcohol in this case, to dry.

All's well that ends well. Thanks for the tip, Joe.

Jon,
I think you jinksed (sp) my mouse! It started not scrolling down today. I was able to do the click, hold, scroll thing, and it started working again.

I plead guilty to jinxing your mouse. Seriously, I'm beginning to think that crud other than oils and stuff on my fingers may be involved. In my area, the pollen and mold spores have been horrendous for the whole summer and I constantly taste the air, have a runny nose, gritty eyes and a tickle in the throat. My cat has to have his eyes cleaned several times a day. I seems to me that that's a factor in gumming up the scroll wheel.

I noticed that, after cleaning the scroll wheel with water, a black film formed around the wheel. It wouldn't come off with water and grudgingly came off with alcohol. There was stuff that looked the same on my car and it wouldn't come off with scrubbing, even in a car wash. In fact, I had to scrape it off my windows. Eventually, enough rain fell to wash it away but it took a lot of time.