Originally posted in September, 2021
The Apple IIe personal computer was manufactured from January 1983 through November 1993. I purchased an Apple IIe several years ago and put it into storage at the time. I recently pulled it out from storage and began the process of refurbishing it. Part of that process was rebuilding the power supply, which I described here.
The power supply appeared to be original to the computer with a date code of 47th week, 1985.
Examining the circuit board showed that the electrolytic capacitors were superior quality United Chemi-con.
By contrast, the line filter capacitor was a RIFA film capacitor of a type known to fail. Cracks were clearly visible in the outer case of the capacitor. It is theorized that these capacitors fail due to moisture ingress which causes insulation breakdown when voltage is applied.
All the old electrolytic and the line filter capacitor were replaced:
Where possible, I used capacitors with higher voltage and temperature rating than the originals.
After reassembling the power supply and reinstalling it in the case, I checked all the outputs. All were within specification.