Getting my flips to flop?

A project log for Restoring the TRANSBINIAC computer

Bringing a vintage DIY binary counting computer back to life

johnJohn 08/27/2020 at 17:570 Comments

The core of this thing are eight bistable flip-flip modules each based around two germanium 2N554 transistors. As-found the machine will power up and illuminate some of the output lights, but the flip/flip triggering is very erratic. Most modules need to be triggered multiple times before switching outputs. Any readers have thoughts on the problem?

Naturally he original sealed paper .05uF 100V capacitors are all suspect at this age. Most measure several times the rated capacitance and show signs of electrical leakage. My first experiment was replacing the caps in one module with a pair of random (0.85uF) known-good films caps I had on hand. The triggering improved a little but is still very unreliable. Correct caps have been ordered, but I'm wondering how much could a drifted cap affect the circuit's function?