Dirty Mice

I’ve talked in the past about cleaning the surface of your mouse.  Now it’s time to flip it over and look at cleaning the bottom.

First a little background on mouse types.  Most mice use one of two basic sensing methods to know how to move your cursor on the screen.  The older mechanical or “ball” mouse had a hard rubber ball inside the mouse.  There’s a hole on the bottom of the mouse that allows a portion of that rubber ball to roll along the surface under the mouse.  The ball in turn causes a couple of rollers inside the mouse to turn.  Those let the mouse know how far and in what direction the cursor should move.

One of the major problems with a “ball” mouse is having dust and debris picked up by the mouse which starts fouling the rollers causing the mouse to “skip” or be unresponsive.  Another limitation was you needed to have an even surface, usually with some sort of mouse pad on it. 

Optical mice use light to perform the same function as that rubber ball.  Unlike mechanical mice, which can become clogged with lint and other debris, optical mice have no open hole in the bottom and no rolling parts.  You can also use an optical mouse on more varied surfaces, including the leg of your pants.  They usually don’t require a mouse pad either.  In fact, some mouse pads actually cause your mouse to not work correctly.  Optical mice do not work well on glossy or transparent surfaces though and we’ve noticed they don’t tend to like the fake wood grain surfaces on some desks and tables either. 

So how do you tell which type of mouse you have?  It's easy!  Turn the mouse over.  If there’s a round hole in the bottom and you can see a grey ball through the hole, you’ve got a mechanical mouse.  If there’s a light shining from a lens on the bottom, you’ve got an LED optical mouse.  Technically there’s a second type of optical mouse, the laser mouse, but they are not too common yet.  They look almost identical to the LED mouse, but they don't have a visible light shining from the lens on the bottom.

 So how do you clean them?  First I’ll talk about optical mice since they’re easy to clean.  If you optical 
mouse isn’t responding well, you can first just try turning the mouse over and blowing on the lens area to get rid of any dust that might be on the lens.  If that doesn’t work, you can try wiping off the lens area with a soft, lint free cloth and a little bit of isopropyl alcohol.  Be gentle and make sure to use a soft, lint free cloth and not a paper towel and to not use much alcohol.  You don’t want to scratch the lens or squeeze any of the cleaner into the LED area.

If the mouse is still acting erratically, try changing the surface under the mouse.  If you’re using a mouse pad, try it without the pad.  If you’re not using a pad, try it over a plain sheet of white paper.  If it works without the pad, you can either continue to use it without the pad or you’ll need to get a different mouse pad.  If it works on the plain paper but not on the desk, you may need to get a mouse pad. 

Mechanical mice take a bit longer to clean, but it’s still a pretty simple process.  First you need to  remove the cover for the mouse ball.  Turn the mouse upside down and take a look at the area around the hole.  That’s the cover.  Use your finger tips to turn the cover counter clockwise until it stops.  Cup one hand and gently turn the mouse over into that hand.  This should cause the cover and the ball to fall into your hand.  Wipe the ball with a soft, lint free cloth to remove any lint, dust, hair or other debris.  If there's still junk on the ball, you can wash it with warm water and a little bit of mild soap and then let it dry.  Take a look at the inside of the cover and wipe off any debris you see there as well.  Put the cover, flat side down, on the desk and put the mouse ball in the center of the cover to keep it from rolling away easily. 

Next, take a look in the hole in the bottom of the mouse.  You should see three rollers.  Two are often long bars and one is a wheel.  Take a look on those rollers and see if there’s a “ring” close to the center of the roller.  It might look like it’s some sort of rubber ring on the rollers, but it’s not.  It’s the junk that’s built up on the rollers from use.  (Icky!)

You need to remove any “rings” or other debris from the rollers.  One of the easiest ways is just to use a fingernail to lightly scrape the stuff off.  You can also use a cotton swab.  You don’t want to use anything that might gouge or scrape the roller surface, nor do you really want to use anything wet in here.  Once you’ve knocked the junk off the rollers, tip your mouse back over while it’s over a garbage can and shake it slightly to get the scraped off remains out.  You can also use compressed air to blow out any other debris in the center.

Turn the mouse onto it’s back again and drop the ball into the hole.  Put the cover back in place.  There are tabs on the cover so you may have to turn it a bit to get it into the right position to lie flat with the rest of the bottom of the mouse.  Once it’s lying flat with the bottom of the mouse, turn the cover clockwise until it stops to lock the cover back in place.

There's one other place you might need to clean on the bottom of the mouse.  On each mouse there are a series of pads that help the mouse glide over surfaces.  Over time these will pick up dirt and can cause your mouse to stop moving freely.  Other than making sure you don't gouge the pads and making sure you don't get any cleaning liquid into the inside of the mouse, you can even use a paper towel dampened with mild soap and water to clean these.