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 <billdegnan at 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