 The magazine of the Melbourne PC User Group Mouse Ablutions Norman Cave |
One of my friends, who knows of my inquisitive nature and itchy screwdriver, gave me a defunct mouse the other day with the suggestion that I may like to pull it apart and see how it works. I didn't need to take it apart to see the problem, I had encountered it before with my own mouse. There was a heavy deposit of "gunk" on the rollers that the ball runs against. This coating of gunk can become quite thick without a noticeable effect on the operation of the mouse but let some of it flake off so that the surface is no longer perfectly circular and one or both of the active rollers cease to rotate, the mouse ceases to move the cursor, left-right, up-down or both.
It is a simple matter to clean the rollers, no great skill or special equipment is required. The first step is the hardest, turn the mouse on its back and remove the cap that retains the ball; a quarter turn or a slide, using the finger tips, in the direction indicated will release the cap and the ball can be tipped out onto your hand.
Now examine the innards of the mouse, you will easily identify the three rollers arranged around the space in which the ball is housed. If the mouse has had some use you will probably see some evidence of gunk as a narrow track on the rollers where they make contact with the ball - it may even appear to be a raised collar that seems to be the way it was made.
The rollers may be of highly polished metal or of plastic but both need to be treated with respect - don't attack the gunk with anything harder than a tooth-pick. The deposit needs to be softened by a solvent - alcohol of some sort seems to be the safest for both you and the mouse, even the vapour from some common solvents will attack plastics and some solvents are also toxic. I use methylated spirits, safe on plastic, mildly toxic if inhaled but flammable.
A cotton bud can be used to apply alcohol to the rollers, leave them to soak for a few minutes, don't be impatient. If you want to have a poke, then use a tooth pick. I sometimes use the point of a pencil - one of the fine lead retractable type. A stiff-bristled artist's brush is good for a heavy deposit, you can give the surfaces a bit of a scrub. Make sure the whole surface is subject to the treatment and the rollers move freely.
As the gunk softens it will peel off and can be removed on the cotton bud or brush, capture as much as you can but don't fret if some fragments elude you. There is nothing inside the mouse that can be damaged, in fact the ordinary mouse is a gutless wonder - four switches, a dozen electronic components and a chip on a circuit board.
Give the ball the treatment too, it will only need an application of alcohol wiped off with a lint free cloth or tissue before returning it to its place.
The gunk that is deposited on the rollers has been picked up by the ball from the surface on which the mouse is used, so it makes sense to attend to that also. The mat I use is a fairly dense foam sheet with one surface covered with a woven fabric, which I assume is intended as the working surface. I wash it as I would wash my wool socks (if I had any and had to wash them) by hand with warm water and soap.
Some feedback on the subject of materials for mouse mats would be appreciated, there may be some more suitable than others.
Reprinted from the March 1995 issue of PC Update, the magazine of Melbourne PC User Group, Australia
