Have been working on debugging an early gen Defender CPU board and got it booting up with no errors. However when it goes into setup mode all I see for the parameters are question marks and it will not let me change anything.
Looking at the schematic the initial guess was the coin door write protection switch was the issue, but checking all the gates with a scope show everything to be in order. Also can't seem to manually put it in self test mode.
What else could be causing this issue? Bad CMOS RAM?
Thanks,
Tim
Looking at the schematic the initial guess was the coin door write protection switch was the issue, but checking all the gates with a scope show everything to be in order. Also can't seem to manually put it in self test mode.
What else could be causing this issue? Bad CMOS RAM?
Thanks,
Tim

