Take inmind I'm a total noob here, but here is what I did. I started tracing The main power coming in. This cab is neat because they placed AC outlets in it for the laser disk player in two locations, so I can check if power is getting to those locations.
The main power is getting to the cabinet fans and to both outlets (when I turn the switch), as well as the marquee light. Those wires all direct. Then the wires go into teh nest of mounted hardware. I dont know if they are all power supplies or inverters, hell, I dont even know exactly what an inverter is. All I know is, the red wires that come out the other side, which go to the monitor are not getting juice. I have to verify this with a volt meter still though.