PDP-8/E PSU Debugging (was Q-bus pinout)

At 07:09 PM 4/9/99 +0100, Tony Duell wrote: Actually I did as suggested and unplugged the wiring harness that plugs into the PSU and then the back plane. I put my DMM on the connector pins on the PSU and the 5V line shows the same behaviour (higher value which quickly drops to 1.5v) I've got both jumpers pulled and all the cards in the front back plane and the system runs (caveat some issues on the Front panel itself such as the 'STATUS' and 'STATE' displays aren't correct) The fault appears to be inside the PSU wiring harness somewhere. Yes, and at this point it has been removed and is sitting on my test bench. Access to the wiring harness is a pain in the fundament! This thing must weight 75lbs all by itself. My current area of investigation is into some of the crimp on connectors on the filter caps to see if perhaps they've oxidized. On another tack, the chassis I got did not come with any covers. I don't know if this is "standard" or not. (I know the PDP-5 isn't designed to be run outside of the rack its built into) The later 8's like the /f and /m in the "mini" cases (one backplane) are covered when they are out of the rack and so that has left me curious. I'm probably going to build a display rack for it anyway with clear sides so that folks can "see" the innards without risking getting fingers in them. Thanks again Tony, --Chuck P.S. I'd like to thank Allison for relating the story of bringing up her 8/F since it inspired me to move forward on this project (code named "FrankenEight" as it is a PDP-8 built out of parts exhumed from dead 8's or other mysterious sources ...)