That is a BA11-M box with a H780 supply. The schematics can be found in the
KC780 document since the front end processor of the 11/780 is a PDP-11/03
with a RX01 drive.
In the end of this document there is a schematic:
Good luck!
/Mattis
Den mån 13 mars 2023 kl 10:57 skrev Holm Tiffe via cctalk <
cctalk(a)classiccmp.org>gt;:
Hi all,
I have to repair an PSU of a 11/23 n a BA11 Box with an H9720 Backplane
(with an KDJ-11A) that has run an CNC milling machine until 2 weeks
before now. :-) This is a Fidia machine..never heard about it before.
The problem is that a big 19000µF 40V capacitor in the PSU has failed
and that I think because of that the 2nd of the two Nidec fans has
finally failed.
I'm in the process of cleaning the goo from the PSU-PCB, found a burnt
5A fuse and now I'm checking the Semiconductors...
The problem is here that the Transistors (and diodes) have uncommon
types printed on, an TO220 is named SJE2677, another one is labeled
12652-00 RCA..and so on.
I've found a label with "0H780-B" on the PSU.. H780 PSU?
Where can I get some schematics from that beast? It is a secondary
switcher ist seems.
Regards,
Holm
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