> A have an A-155 that used to be connected to an A-154. I have re-
> attached the ribbon cable to ST2 and the busboard connection to ST1.
> The A-155 powers up, but it will only address steps 2 and 4. What is
> the problem here
>
> Thanks in advance,
>
> Matt

Difficult to diagnose. If the cables are connected in the right way (not
reverse, not displaced) the A-155 is probably defective and has to be
repaired. I'd suppose the problem is the counter circuit on the small
control board that generates the addresses (CD4024).

Best wishes
Dieter Doepfer