Today we’re going to future proof my Commodore 128 from the attic. Or at least improve its chances of surviving the next 30-40 years in good working order. The process has several parts: recapping and cleaning.
Recapping means replacing the electrolytic capacitors on the circuit board with new ones. Electrolytics — these are the big blue or black cylinders — are filled with a kind of electrolyte gel, and over time this can start to dry out, or worse, leak. A leaking capacitor will start to corrode and eat away the circuit traces and other components, eventually destroying the computer. The capacitors on my 128 don’t show any signs of leaking, but they can still have dried out, resulting in a capacitance that is at best out of spec, and at worst a ticking time bomb. Generally they are rated to last 10-15 years, not the 35-40 of these computers. So replacing them is definitely a good idea.
The next thing we’re going to do is pull the ICs from their sockets and clean both the chips and the sockets with some electrical contact cleaner before putting them back. This will ensure they make good contact and aren’t loose. We can inspect them at the same time for bent legs or any signs of corrosion.
With the chips replaced, I’ll be adding heatsinks to them. The old RF shield has tabs that bend down onto the chips, but rather than keeping things cool, it seems just to restrict airflow. The design of the 128 leaves very little internal space, and as there’s no real need for RF shielding these days, it’s better to get rid of it and add some proper heatsinks.
Finally we’ll put it all back together and see if our efforts have made things better or worse. Oh, and maybe play a little Attack of the Petscii Robots…