Dear list members, I was wondering if anybody is aware of VAX 86x0 schematics having

It seems that DEC never published such details as schematics for the

However, maybe Hewlett Packard handed DEC-internal documents over to a

Any pointers would be greatly appreciated! Best regards, Pierre

http://www.digitalheritage.de

Dear list members, I was wondering if anybody is aware of VAX 86x0 schematics having survived the product life cycle within DEC? I searched the web extensively but could not find any hints on this. It seems that DEC never published such details as schematics for the successor of the VAX 11/78x systems, not even on microfiche, maybe due to the macrocell array implementation (just a guess). All I could find is that there were illustrated parts list on microfiche. However, maybe Hewlett Packard handed DEC-internal documents over to a museum such as the CHM? Or a former designer still have schematics in their archives? Any pointers would be greatly appreciated!

That makes some sense. Print sets were needed in older machines because FE would actually replace failed components on a board. With "swap the failed board" repair procedures, it isn't all that useful for support engineers to know how a board works, much less what the detailed circuitry looks like.

Same here. The FE came prepared with a replacement board. Never repaired the board. In and out!

Same here. The FE came prepared with a replacement board. Never repaired the board. In and out!

On Jul 3, 2025, at 2:26 PM, Wayne S via cctalk <cctalk(a)classiccmp.org> wrote: That’s a good business practice anyway. You want your high price system up and running as fast as possible, so not having to do more than cursory diagnostics is a good thing I think deck realize that with the VAX and it’s remote the diagnostic capability as for the board breaks, IBM used to do that for all the boards they replaced. They even had a special board breaking tool. My CE from IBM said that it costs IBM more to diagnose a faulty board than it does to make a new one so that’s why they do it. Breaking the board also ensures that the engineers won’t get caught up in a side project trying to figure out what went wrong.

Yes, stats are kept about issues. Someone should look at the stats and start to investigate when there’s a lot of failures with the same issue. Explicit instructions should be sent to field engineers to take extra steps to document what they found and how it was resolved, and report their conclusions back to the investigation leader. That’s how IBM did it. I know DEC kinda did it for software on VMS though their “Software and Solutions” database. I really liked looking at that. Sent from my iPhone >> On Jul 3, 2025, at 12:52, Paul Koning<paulkoning(a)comcast.net> wrote: > >  > >> On Jul 3, 2025, at 2:26 PM, Wayne S via cctalk<cctalk(a)classiccmp.org> wrote: >> >> That’s a good business practice anyway. You want your high price system up and running as fast as possible, so not having to do more than cursory diagnostics is a good thing I think deck realize that with the VAX and it’s remote the diagnostic capability as for the board breaks, IBM used to do that for all the boards they replaced. They even had a special board breaking tool. >> My CE from IBM said that it costs IBM more to diagnose a faulty board than it does to make a new one so that’s why they do it. Breaking the board also ensures that the engineers won’t get caught up in a side project trying to figure out what went wrong. > That's true for problems seen occasionally. When people realize a particular issue appears "too often" it does become an engineering matter, because then it indicates an issue with design or manufacturing or part selection. > > For example, I remember a product that had a memory backup battery issue, which turned out to be a change in plating for the battery holder. For engineering it turned into an exercise in learning what "electrovoltaic series" means -- not something familiar to most digital logic EEs. > > paul >

Yes, stats are kept about issues. Someone should look at the stats and start to investigate when there’s a lot of failures with the same issue. Explicit instructions should be sent to field engineers to take extra steps to document what they found and how it was resolved, and report their conclusions back to the investigation leader.

On Jul 3, 2025, at 2:26 PM, Wayne S via cctalk <cctalk(a)classiccmp.org> wrote: That’s a good business practice anyway. You want your high price system up and running as fast as possible, so not having to do more than cursory diagnostics is a good thing I think deck realize that with the VAX and it’s remote the diagnostic capability as for the board breaks, IBM used to do that for all the boards they replaced. They even had a special board breaking tool. My CE from IBM said that it costs IBM more to diagnose a faulty board than it does to make a new one so that’s why they do it. Breaking the board also ensures that the engineers won’t get caught up in a side project trying to figure out what went wrong.

Which makes sense. My guess is in the 80's 90's they would send the board back to a rework facility and repair it there. BGA/PGA is not too difficult to do if you have a good rework station, and the rest of the chips on the board were probably worth enough to make the rework totally feasable. By the mid 2000's, yeah they probably would just trash the board. C

On Jul 2, 2025, at 11:13 AM, Jon Elson via cctalk <cctalk(a)classiccmp.org> wrote: On 7/2/25 06:08, P Gebhardt via cctalk wrote: I did have a KA630-AA print set at one time.  That was about the latest prints I have seen. Jon