Excuse my noobness, this is my second pin (well kind of pin).
I picked up a non-working Hyperball. When I was making the deal all that would power on were 4 of the backglass flashers and the fan for the big solenoid. The MPU display would also flash 0 when you flipped the power.
Got it home and no power to anything. No zero flash. Hitting the black button on the sound board does not result in anything. I shocked myself reaching around in the bottom of the cabinet, so there is at least power entering the cab.
No obvious burned up stuff. GI Connector is fine. No battery damage.
I checked the fuses on the Power supply and none are blown (although they all seem to be the wrong fuses). Did not pull the Cab fuses as they did not come out easy, but I will if that is the ob next step. Superficially, they do not look blown.
I have a known working Power supply from a system 9 that I can swap in, but I read that if the sound test does nothing then one should not start with the power supply.
Where should I start?