Hi Paul;
I just got finished troubleshooting my Front Panel, as it would not stay in the stop mode, it would always stay in 'RUN' mode, which I traced to a Bad Ic, on the Front Panel, The stop/Run Flip-flop was not working right. The Scope made it so I could LOOK at its input and its output, and since it could not pull the signal 'low' it would stay in Run mode.... So, yes Paul , a scope is a nice thing to have....
THANK YOU Marty