HP 9100A No Display

[aj04062]

Seeking technical help, parts, guidance, you name it to try and resurrect a 9100A model. Previous owner claimed everything worked except the core memory board. This was determined through board swapping with his other machine. I'm now handicapped to diagnose as I don't have this reference.

A few months ago, I checked the power supply to the Service Manual available on HPmuseum.net and everything looked fine as I recall. I've also cleaned the edge contacts and double checked their seating on the main boards but didn't do the sideboards as Tony D calls them.

I do need to check the clock, flip-flops and mains sync signal per Tony's comments on thread

Since this early, simple testing, I commissioned some extension boards to fit into the dual slots. This will allow me to raise the core memory board above the others to probe. Thing is, I don't know what I'm probing for!