Hi Charles, The H786 was standard for the 11/23, BA11-N. The H7861 was for the 11/23+, BA11-S and had afrw more amps of +5 volts.
I would start by looking at the electronic caps. I have a few extras here but am pretty busy for the next week or so. Paul On Sat, Mar 30, 2019 at 2:25 PM Charles via cctalk <cctalk@classiccmp.org> wrote: > I have a PDP-11/23+ and the power supply (H786) "last ran when parked" a > year or so ago. But there's no DC output at all today, and the fans are > running so there is AC power... > I also have the original H7861 that came with it, which had a blown > chopper > transistor. I couldn't find anything else bad, so I replaced the > transistor > and within a few seconds of running, it blew again. :( > > So I need some help - I've never been good at fixing switching supplies, > not > to mention the high-side hazards. > The simplest solution would be just to replace it with a working unit. > Anyone got one to sell, hopefully cheap? :) > If not, can anyone fix one or both of mine? > > thanks! > Charles > > >