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All CPU board are essentially the same. They need power,
one or more clock circuitries, a reset section, they move data from the
ROMs to CPU to RAMs (or some to RAM then to CPU) via decoders and latches/buffers
and finally to an output stage be it video or audio, and don't forget the
input section.
Here are the basic steps to take:
1) Make sure you have a good PS (check power on the game board).
2) Check all your clock circuitries.
3) Check your reset circuitry.
4) Check to see if your CPU is getting it's vital signals.
5) Check your Address and Data lines.
If all the above are working then you should see some life from the board;
next check your outputs and inputs.
That's all there is to it, oh yeah and some luck on the more stubborn boards
and lots of test equipment and good schematics (knowing how to read them
helps) and some experience knowing what section to check out in more detail
and most of all knowing what boards to stay away from.
Good luck....