What happens when you put the machine in display test?
I’m in Ocala, perhaps I could give you a hand.
I have a dozen of these classic Ballys.
Jim.

On the displays the don’t work, what is TP2 read? Caution, high voltage!

When I have display problems, the first thing I do is reflow the header pins. They get cracked because of the
force it takes to seat the plug.

If you want to work on these machines, you have to use a meter. People here can give you all kinds of help, but we need readings.
Do you have hv at tp2 on every board?