I recently got my hands on a couple of Atari 800's and peripherals (disk drives, printer, cartridges, floppy disks). Before I start using this equipment, can someone point me in the right direction as to what are the most basic steps to do to remove dust and grime that's been accumulating since ~1985. Could rubbing alcohol be used on the cartridges and the cartridge slots? How to clean keyboards? Anything to do to disk drive? I'm guessing there might be a user group or articles addressing these questions but have not found them.
For surface dirt, I normally use foam cleaner. It's kind of like soapy water in a can but has less crud in it and doesn't slop everywhere like actual soapy water. Spray on, and wipe off with a cloth. Don't be shy with it; it's hard to use too much. Way back in the 90s when I was working for a shifty TV dealer, we'd use it extensively to tart up old stuff for resale. It is sometimes also sold as whiteboard cleaner, however not all whiteboard cleaners are foam cleaner, so check the ingredients.
Foam cleaner can be used on PCBs, but only as a last resort due to so much grot and crud (e.g. it used to be owned by a smoker or has had a hard life in a factory) that they need cleaning. The problem seems to be that it is slightly conductive and/or capacitative so it interferes with the board's operation. It shouldn't cause it to blow up if you turn it on earlier, but I recommend you leave the board to dry out for a day or two before testing.
For connectors and switches, you want contact cleaner. It should come with a straw so you can direct it more accurately into the switch mechanism and along the edge connector. Use enough, but not too much, as the oil gets everywhere. You may need to dig the foam cleaner back out if you were too generous :)
Both of these are cheap. I paid €5.24 for my last can of foam cleaner and about the same for contact cleaner.
Just vacuum the big stuff, dust off with a soft tissue, rub sticky stuff with a wet towel and if necessary rinse with water. Use soap on plastic, and again rinse. If water in your area is particular, use demineralized for the last rinsing. Give it a good and thorough dry.
In fact, even using a dishwasher (after taking it (the computer, not the dishwasher) apart and removing bolts and metal pieces as well as cables) might be fine. Don't put it on hot and no detergent, or at maximum some soap. Rinse afterwards once more, dry throughout and enjoy.
If PCB contacts are still malfunctioning (shouldn't), a rubber (*1) is best to remove potential thin layers of rust.
Beside that, checking other, alike questions (and answers) might help:
- How safe are modern motherboard-cleaning techniques for this 1987 Soviet portable computer?
- What should I do to clean up a Power Mac G3 that's been outside for two years?
- How should I clean the plastic exterior of my computers and parts
(Just a quick selection, there are many more)
*1 - that is a classic soft pencil eraser. Do not use any other eraser, hard ones, or glas fiber based ones, as they will scrap away the cover (gold) layer and lead to massive rust.