>> It is also possible that a capacitor has deteriorated in the >> timeout one-shot > > I was beginning to wonder if it was a capacitor
FWIW, while restoring my 11/45 and its RK11-C, I found several failed 74LS123 dual one-shots in various places. Haven’t looked at the RL02 drawings yet, but it seems it was a popular part in DEC designs; if you have one there it might be a more likely fail than the associated small-value timing caps which tend to be fairly robust ceramics? They are pretty easy to diagnose with a chipclip and a logic analyzer. —FritzM.
