I just acquired a Williams World Cup (System 3). I am having an issue with the ball return. When I got the machine, none of the solenoids were working. I replaced the fuse, and everything except the ball return will work. It gets power from a test light, but will not fire even if I ground it out manually; it will blow the fuse. Solenoid does not have visible appearance of being melted.

I am not sure if I should be looking at a board issue, or solenoid issue. This is my first time working on one of these machines.

Cheers