Vintage computer cleaning and maintenance

by Kevin Stumpf

Be advised - cleaning computers can be bad for your health because you are dealing with contaminants and chemicals. To go beyond cleaning and making cosmetic repairs requires sound technical knowledge of electricity and electronics. Repairing old computers can be dangerous - be safe, don't do it unless you know what you're doing.

Cleaning

Your job now is to remove all sorts of stuff from all sorts of stuff - molds from documentation sleeves, water marks from CD-ROMS, tarnish from plastic or metal hardware cases/covers, gooey remains of tape from keyboards, etc.

You must accept the health risks of working with dusty, moldy, smoky, dirty things and the chemicals you might use to remove them. When cleaning mold-covered materials you should work outdoors. Older computers might have been built before the ecological movement enlightened us about the damage we were wreaking on the environment and ourselves so beware of chemicals that seep out of cabinets and treat them carefully. They could be toxic.

Making a habit of wearing surgical gloves when you clean your computers is a good one to start. It serves two goals. Gloves will protect your and you will protect what you're working with, especially optical and magnetic media, and paper (i.e. books, empire, punched cards, etc.)

Question: what do plastic and metal surfaces of computer covers, cases, or cabinets and kitchen fridges have in common? They're all great for taping things onto. You might find instructions for gaining access to a now defunct on-line system on your collectible computer or something like that. These notes might be useless or they might be a significant part of the history of the computer You might be able to pull the tape off without leaving any residue, but usually tape leaves a gooey mess behind.

How do you safely remove sticky residue from tape? How do you clean smoke from plastic surfaces? How do you restore the original color of plastic surfaces or remove grease pencil markings? Chemicals, that's how. I do not officially endorse any of the following products... but they come highly recommended and they form a starting point for you to begin experimenting:
- Touch of Oranges - stickiness, crayon, grease from any surface
- 3M GP Adhesive Remover - for stickiness
- Purple Stuff - for discoloration
- Fulcron - for discoloration
- Antistatic Foam Cleaner - for discoloration/markings
- Cameo Copper Cleaner - ink/marker

Authenticity

I don't want to appear fastidious, but discriminating computer collectors prefer to use authentic parts and software. At least make every effort to source and acquire them. Substitute parts and software are sometimes just not an alternative due to product specifications. When substitute parts will work, use them as a temporary solution only and continue searching for the original ones.

We all know that someday authentic parts, software, and documentation will have withered away, but that's a different story. After that point in time you will be considered clever using or developing substitutes, but until then attempt to use the authentic parts.

Before you switch it on

Working safely and properly with electricity and electronics isn't something you can learn in a short chapter in a book about collecting computers. The following discussion is intended to give you a glimpse of the scope of the job and shouldn't be interpreted as guidelines.

Before you switch on your latest acquisition you should first give both the exterior and interior a thorough cleaning. Next inspect all electrical connections and circuitry.

What should you look for?
- Evidence of smoke, water, or corrosion;
- Loose screws;
- Cold (broken) solder joints;
- Bent pins;
- Blown or missing fuses;
- Melted capacitors;
- Burnt resistors;
- Whatever else is suspicious and;
- Whatever else is appropriate for the hardware you are working on.

After the inspection, remedy each problem. If you discover traces of smoke or water you should inspect the area thoroughly looking for causes and closely checking near-by components for damage. Basically then you tighten the screws, straighten the pin, replace or install fuses and any other components.

Another good practice is to remove and re-seat all components that aren't soldered to the printed circuit board, and do the same for all boards plugged into the bus/backplane/motherboard (e.g. remove and re-seat a modem card). Next do the same thing for all inter-board connectors (ribbon cable, etc.). Then clean all pin and edge connections before you re-seat them. Pink erasers do a good job on edge connectors and toothbrushes can be used on pin connectors.

Next try to make a copy of the contents of any EPROMs, ROMS, and PALs. You must have special equipment and knowledge to do this.

Finally make sure the power supply works properly. Do this by disconnecting the power supply from the rest of the hardware and attaching a dummy load to it. Plug it in and listen for loud humming or other unusual or unexpected sounds coming from the power supply.

After you switch it on

After booting your computer for the first time listen to the hard disk drives. If they squeal you might have a mechanical problem. Next proceed to exercise any diskette drives. Format a diskette in each drive and write and read files to and from each drive before you try to read any diskettes containing valuable data or software.

Next you must check for unexpected data on any storage devices or media. It often happens that the last owner isn't the last user and the last user didn't erase or remove all the data that should have been removed. I once acquired a CADO Tiger (mid 1980s) from a man who explained he acquired it from a rural hospital. He was warned by the hospital it might still contain private records. This should have surprised me, but it didn't. Such is privacy in the Information Age.

If and when files containing someone or some company's data is found on the used computer you call your own, you should destroy them immediately.