Hi all, hope you can help.

Have been fiddling with my Space Station including adding mirror blades/ repaint
I now have a really loud hum coming through the speakers, this i can tell by unplugging them from the board or turning the volume up/down.

I think the origin of this is from the transformer - it's hard to pinpoint.
Can this be to do with the ground braid? Or may the transformer be faulty?

I have been unscrewing/rescrewing the braid as the coin door and side panels have been off.
I made the decision to ground the mirror blades to the point where the siderails are bolted as that seemed to make sense. It's always puzzled me that blades aren't connect to the ground when everything else is.

I don't think though that the noise happened straight away. It was hours later when I turned it back on. I would have noticed.

The transformer's screws were fairly loose, but tightening them made no difference. Is this correct that the buzz would be picked up by the speakers (for whatever reason)?

Thanks folks.