1541 Alignment disk

On Jan 29, 2014 1:50 PM, "Chuck Guzis" <cclist at sydex.com> wrote: If it perchance does, once every 20 years should do. I think I'd recommend no less than every 5 years for the electrolytics, and preferrably more frequently than that. I'd probably power up for a few hours each time, if the equipment hadn't seen any other use. electrolytics, but drying out of the electrolyte in my experience has been more of a problem. The drying out depends on the brand and vintage. If the capacitor was sealed properly when manufactured, and hasn't been abused (electrically or mechanically), it shouldn't dry out for many years. We had few if any dried out electrolytics in the then 40-year-old PDP-1, but many that needed reformation after only a decade since last powered operation. As far as I know, modern aluminum electrolytics still work the same way, so they are still prone to oxide breakdown. It's a fundamental characteristic of the product, not a manufacturing defect, unlike e.g. a substandard seal or an incomplete stolen electrolyte formula. At least one aluminum electrolytic capacitor manufacturer had an app note about reformation on their web site when we did the restoration. The oxide breakdown is a progressive degradation, not a step function, and different circuits (even in the same product) operate the electrolytics at diiferent actual working voltages (as compared to rated maximums), so it is difficult to give a one-size-fits-all rule of thumb regarding minimum operating intervals and periods.