Great to see you got it sorted Dave but problem with this blanket swap everything out approach is that you never actually found or know the source or the noise.? . . This means you may still have the noise and just masking it out.! . . For now.!!

If it happens again or if others have similair issue it's much better if you can track down the source of noise. Often noise comes from one area or component and can be sign of component starting to fail. Often it's poor quality components, Esp with Cheap Bob's cauisng the problem.

To be honest I've never understood why people try to take short cuts with wiring because it's no harder to do it correctly and saves so much headache and time further down the road.