Ill give you the same advice I give everyone when they are starting. Start at the wall and work your way in. Follow the power. See what the voltage is coming from your outlet and then follow the flow of power as it enters the machine thru the power cord up thru the transformer into power board. After that you can start worrying about the mpu, but until you know you have ALL the power going where it needs to, the game will never boot.

If your in your first machine, I would sent it in. That board isn’t that hard to work on but it is a bit expensive to replace. Get an old bally when you want to start working on boards. Easy to get replacements and super simple to work on. Thick traces that almost never pull out