Alright, thanks for all the helpful tips and information. I guess what I'll do when disassembling it is note down every electrolytic, and probably just throw them all into a Digikey order that I'm working on for other repairs.
Probably will give reforming a try if it seems practical, but I assume on the power supply that's going to mean desoldering one leg on each cap. At that point it's probably better to just replace the cap. My only worry would be obsolete/oddball cap values that I'd have to inspect the circuit to see what replacement I can use, eg. 290uF and 250uF caps. On another note, has anyone ever tried making their own I/O boards for any of the 2100 series computers? The closest I found was http://newton.freehostia.com/hp/ where he makes a paper tape emulator and disk interface. However both of those are designed to connect to an existing I/O board like the "microcircuit interface". I haven't seen anything yet on how to interface to the I/O bus, but then again there are thousands of pages of manuals still to browse through. On Tue, Aug 2, 2016 at 10:42 AM, Glen Slick <glen.sl...@gmail.com> wrote: > On Mon, Aug 1, 2016 at 10:25 PM, Lyle Bickley <lbick...@bickleywest.com> > wrote: > > On Mon, 1 Aug 2016 22:11:17 -0700 > > Bob Rosenbloom <boba...@sbcglobal.net> wrote: > > > > --snip-- > > > >> There's a bunch of small electrolytic capacitors on the Inhibit > >> Driver Load Card, A106, that needed to be reformed before my memory > >> would work reliably. > > > >> They reformed themselves in one of my units. I had memory errors for > >> an hour or so then they went away. On other units, I reformed the > >> caps (took the board > > > >> out and slowly brought it up on a bench supply), and had no memory > >> errors at first power up of the system. > >> > >> Bob > > > > I had exactly the same problem with the capacitors on a spare Inhibit > > Driver Load Card. Most would not reform so I just replaced them with > > modern caps. The board (and memory) worked perfectly after that. > > > > Lyle > > That is good information to know. I have a 2100A that I haven't > touched in a while. It had memory issues that I never got around to > trying to debug. Next time I work on it I'll look at the IDL card. >