Speaker noises (Model 3)

[meyerli]

Hope my description is more or less understandable. As not native english speaker it's difficult to describe such for me.

Let's try anyway:
As soon as the arcade is started all 4 speaker are giving a background noise. The rear speakers (within seats) are louder and due to distance to head more annoying. When music starts the background noise is not noticable anymore. Turning up or down the volume doesn't influence on the background noise.

It's related to a Scud Race Deluxe, which has all the boards (game, sound boards, power supply, etc.) within monitor stand. As I have 2 of those monitor stands with all the boards I've swapped them but the background noise on the speakers remains the same. To ensure it's not an issue with cabling I've connected one of the speakers directly to the AMP but still the same. Also tested another 8 ohm speaker from home but no luck as well.

Not sure what else I could check to identify the root cause. Maybe somebody has an idea?

Also noticed that my multimeter measures continuity between + and - of every speakers. Is that expected behaviour?

 

[Ringo]

Try grounding the game cage to a ground point on the cabinet.

I had a similar issue with Scud Race when I installed it in a Sega Rally 2 cabinet. Your issue maybe related to something else, but, grounding the cage helped in my situation.

 

[meyerli]

Try grounding the game cage to a ground point on the cabinet.

I had a similar issue with Scud Race when I installed it in a Sega Rally 2 cabinet. Your issue maybe related to something else, but, grounding the cage helped in my situation.

Thanks a lot for the advice. The cage indeed wasn't connected to ground. Unfortunately connecting it didn't solve the issue.