This post is going to help you in doing core maintenance of your wired electromechanical (trackball one) and wired optical mouse (with LED – Light Emitting Diode generating light and its detection) by giving you directions on their internal cleaning.
I don’t have an electromechanical mouse, so I won’t be able to show you the relevant pictures of its cleaning operation done from its back.
If you are facing problem with only dragging of your computer’s electromechanical mouse (the cursor going haywire) then you can do the following:
- Switch off your computer after its proper shutdown.
Pull out mouse cable from the back of the CPU and take it away at some distance so that the dirt and dust that you clean doesn’t go to the other parts of your computer. If that’s not possible as your mouse wire is fixed with other wires, don’t worry. Follow the same procedure as given next.
- Keep a sheet of clean newspaper/paper/cloth under the mouse and invert it so that the trackball part faces you.
There will be a circular plastic cap that will be stopping trackball from coming out yet allowing the mouse track ball to rotate. Check the direction of the arrows in which you have to move the circular cap to let the track ball come out. Normally, rotating the circular cap in anti clockwise direction removes trackball cap from its position and let the trackball comes out.
- After the trackball has come out, clean it thoroughly with a clean cotton cloth rinsed with isopropyl alcohol. You should clean the track ball until it appears clean and pleases you look wise without any dirt or grease on it. The purpose of cleaning track ball is to make it non-slippery and ultimate clean close to when it was new.
- Now with the cleaned trackball outside, you should similarly clean the three small sized wheels (has attached sensors to detect the mouse movement in a particular direction) that touch the periphery of trackball when it’s inside. You can use the cotton cloth rinsed with isopropyl alcohol to do so. While cleaning these three wheels, apply slight pressure and remove the dirt and grease etc. on their complete surface and wherever you could see inside the electromechanical mouse. You can also use a good quality brush rinsed with isopropyl alcohol to do thorough cleaning of optical mouse from inside.
- After the trackball and the mouse motion detecting wheels have been cleaned, you should fit the trackball back in the inverted mouse and tighten the circular plastic cap that holds the trackball in its position (Rotating in clockwise direction should do it). You can now connect the electromechanical mouse to the computer by connecting its connector back from where you pulled it out. After trackball and sensor wheels cleaning, your mouse movement should now be fine (if it was due to the dust and dirt only).
Now, On to internal cleaning operation of optical mouse that will help its users having problems in dragging, dropping, clicking and scrolling while using it. Yes, it can sometimes happen that you face all these problems simultaneously if you haven’t cleaned your optical mouse for months. My friends having electromechanical mouse with problems in right and left clicking can also get the clues of opening the mouse and cleaning the click assembly for the tips given next for optical mouse.
Kindly refer to the labeled picture of my DELL Vostro 400 optical mouse with top cover removed and all the main parts shown.
The shown picture will give you clear idea of what I am writing next. So, here is what you can do to do a complete cleaning of your optical wired mouse:
- Shutdown and power off your computer whose optical mouse internal cleaning is to be done.
- Either remove the optical mouse connector from the back of the system so that you can take it way for cleaning or if you can’t do it, cover other parts of your computer so that they don’t get dirty.
- Place the optical mouse on a clean paper sheet/cloth and invert it so that the LED portion (bottom side that rests on the mouse pad/desk) faces you.
- Normally there is a screw at the lower bottom that keeps the lower plastic cover of the mouse tightened with the upper cover. Also the top plastic cover of the mouse has two plastic female rectangular grooves that fit in the male grooves of the lower plastic body. Remove the screw by untightening it with a star screwdriver with the bit size matching the screw and slim enough to go inside to reach the screw without causing any damage to the mouse screw hole.
- After removing the screw, invert the mouse back to its normal position – the scroll wheel and the left click and right click buttons facing you. There will be a gap between the top and the lower cover of the optical mouse and you can now apply slight force to increase the gap along the whole body of the mouse. You can see the upper back portion coming up. Now to pull out the upper front portion apply some force in the backward direction so that the female grooves in the mouse upper inside portion comes out of the male lower portion.
- Now the top portion of the mouse will come outside and you can see the left click button, right click button assembly (mechanical + electronics in the form of a box) on the PCB (printed circuit board) lower portion. You can now use a good quality brush rinsed with isopropyl alcohol to clean all the parts of the mouse including the top plastic casing, scroll wheel and sensors, LED assembly (after removing the PCB from its latches) and the left click and right click buttons sensors assembly. You can also clean the optical mouse connector also that fits into computer so that it makes better contact with your computer’s mouse connector.
- Allow few minutes for all the parts to dry and then physically confirm that they are not wet. BTW – Isopropyl alcohol is not good conductor of electricity, so even if it is slightly left on the PCB, it won’t harm your mouse and PC when powered ON. After, all the cleaned parts have been physically confirmed for drying, pack them back using now the reverse logic of disassembling them. The most important is to make sure that the upper plastic cover with female grooves fits in the male grooves of the lower mouse portion and the left click and right click buttons click is OK. Don’t forget to make sure that the LED glass cover at the bottom (below the PCB) is fitted properly.
- After you have tightened the screw (invert the mouse to do so) of the lower plastic cover with the upper cover, the mouse should be connected back to the computer.
From the steps given, this cleaning operation looks difficult but when you start doing it with some patience and logic, you will find it easy. It’s not rocket science 
I am sure that after you have done the internal cleaning of your optical mouse as per the steps explained above, your optical mouse will start working normally – right click, left click, drag, drop, double click, scrolling – every mouse operation working fine as it used to work when the mouse was new.
Oh, in case, your time is invaluable and you don’t want to spend time (few minutes) in opening, cleaning and packing your computer mouse back, buy a new one! A brand new good quality wired optical mouse should not cost more than $ 20.
Did these mouse cleaning steps for electromechanical (with track ball) and optical mouse (with LED generation and detection) helped you? I hope yes!
Let me know if I am right?
