Ray Fantini knows the 11/34 very well https://www.youtube.com/watch?v=pU8DOKVxDJ8
He helped me with UNIBUS diagnosis. I am sure you have seen this: http://bitsavers.org/pdf/dec/pdp11/1134/ I would definitely start with the power supply and work my way through the voltage regulators, etc. If you already did this, I apologize for missing that you mentioned. BIll On Mon, Dec 11, 2017 at 8:15 AM, william degnan <billdeg...@gmail.com> wrote: > > > >> > > >> Any suggestions as to what to try first? I may have the bus grant in > backwards. I have other boards I can try. > > >> > > For an 11/34A can one test for DC LO / AC LO? If so and you don't get the > correct reading that's a show stopper right there. Remove all but the > essential cards, terminate the UNIBUS to the shortest poss. size and least > RAM. I no longer have an 11/34A but there are a lot of similarities to the > 11/40. Many cards interchangable. > > Bill >
