There is lots of information available on reforming capactors. Some of it is useful. This is good introduction: http://www.nmr.mgh.harvard.edu/~reese/electrolytics/ A Variac can be used to reform caps in a linear power supply. Linear power supplies were common in older computers. The RICM recently used a Variac to reform capacitors during the resurection of a PDP-8/S. The power supplies in the 8/S were linear ferroresonant design, common in DEC equipment. With these power supplies the voltage on the capacitors will slowly increase in relation to the Variac output until you reach about 45 VAC. At that point the ferroresonant circuit kicks in and the output goes to full voltage. The big electrolytic filter caps survived this, but eventually the AC capacitors in the ferroresonant circuit failed. Replacements for those are easy to find. Newer systems, like the Kaypro, probably have a switching power supply. Switching power supplies usually will not have any outout until the Variac reaches the minimum acceptable input voltage for the power supply, usually something like 85-90 VAC. At that point the power supply turns on and tries to make the full output voltage. That can be really tough on old electrolytic capacitors. Eric Smith, as part of the PDP-1 restoration project at the CHM, developed software to control an Agilent power supply and very carefully reform capacitors. This is probably the best solution. http://www.brouhaha.com/~eric/software/wrec/ -- Michael Thompson