Editing PDP-8 Power Supply Restoration (section)

== Connections, relay and transistors ==
* Clean and tighten every 0.25-inch quick-disconnect (Faston) terminal. On his PDP-8/I Gesswein found corroded Fastons dropping enough voltage under load to cause trouble. On the 708 he looked for unusual voltage drops along the load path with a meter, and for ripple on capacitor terminals with an oscilloscope, which found a slightly loose riveted terminal and one intermittent Faston.<ref name="djgps" />
* Inspect relay K1 (Potter & Brumfield KRP14DG, 12 V DC coil) and its socket.<ref name="f87sch" /> Gesswein's had corroded pins and a damaged contact; he cleaned the socket and fitted a new old-stock relay.<ref name="djgps" />
* Q1 and Q2 are socketed on the chassis. Gesswein reseated them with new heat sink compound, then found one bad during testing and replaced it with a DEC-labelled transistor of the same type.<ref name="djgps" /><ref name="f87sch" />
* Replace the AC resonating capacitor. Gesswein bought a new one because old ones tend to fail, can burst and may contain PCBs; Iowa also replaced C17.<ref name="djgps" /><ref name="ui8" />