Cleaning a keyboard


What should I use to improve the finish of the keyboards on some old calculators I recently bought, without jeopardizing the keyboard functionality - I'm thinking particularly on the area inbetween keys.

I also have one calculator with some dust inside the display. Any way to remove it (it's a pioneer series)?




I've been waiting for someone that really knows what they're doing to answer your post, but as advise seems to be scarce I'll share what I tried. I bought a used 32Sii that had a pretty dirty keyboard and was afraid to use any kind of solvent. I wet the end of a Q-tip with water, and then blot excess water from it with a paper towel, so that no water could be accidentally deposited into the keys. I then gently drag the Q-tip between the keys. I was amazed at how dirty the Q-tip was. I did this several times and even though the keyboard doesn't look 'new' it looks quite a bit better. Like I said, I'm certainly not an expert, and was very careful doing this so take my experience for what it's worth.



Keyboard cleaning can done with a 70/30 mixture of isopropyl alcohol and di water. Regular window cleaner should work as well but your mileage may vary. Spray very, very lightly as not to get liquid down inside the keys. Scrub with a very soft toothbrush and wipe with soft towel. You may need to repeat.

If it doesn't work when done - you got the keyboard internals wet so remove the batteries for at least day until it dries else you'll toast the keyboard.

Very dirty units will end up with "crunchy" keys and this will require an immersion bath to remove. No batteries and distilled water are the solution of choice.

Best way to get dust out of the display window of an early Pioneer is to wedge the tube of a canned-air keyboard duster in the seam of the case - to the right or left of the lcd and give it a puff. BE SURE to hold the can upright so that you don't shoot liquid into the display as you will not like the result. While this has some risk, it is still much lower than trying to open to clean which is no more effective than the tube in the side of the case trick.


Is it safe to use the 7 part rubbing alcohol / 3 part water mix or the window cleaner on the display itself, if you apply it lightly?


The short answer is yes, it should be is fine. I think rubbing alcohol already has some water in it and if so, there would be no need to add any. The stuff I use is an electronic grade product in a spray bottle.

The longer answer:

Pioneer LCD's that do not have the window in front of them are not affected by the usual cleaners - but the polarizer layer that you are cleaning is a rather soft material and can be scratched if rubbed with coarse paper towels. A soft cloth is safer.

Older Pioneers with the display windows - are not bothered by cleaners but they have an anti-reflective coating so a soft cloth is the way to go (same is true of Voyagers). The caution with these is that using too much liquid can end up inside the calculator and on the LCD if the adhesive that holds the window in place is failing. Just go really light with liquids and don't use canned air to blow dry, you can force it inside the calculator. Once inside, it's likely to leave spots on the display.

The isopropyl/water works well for ink and other grunge, if it is just light surface sumduges, window cleaner should do fine. Really dirty machines will need multiple applications to find the paint underneath :)

Beware of window cleaners and alcohols in general on Classic and Woodstock keyboards. They tend to leave nasty white spots where finger oils have rubbed off the clear coatings. Cleaning them is like a box of chocolates - you never know what you'll end up with.

Edited: 8 May 2006, 11:51 p.m.


Am I correct that the 32Sii would be considered one of the older Pioneer series calculators, in that they have the display bezel (window) surrounding the display?


Uh, no. The 32Sii was only built in the later stepped or rececessed bezel style.

Early style with window in front of LCD (sometimes refered to as a "flat" bezel):

Later style without, sometimes refered to as a "stepped" bezel:

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