Thank you all for your help, but alas my mac has turned up it's toes and given me the "Checker board" of death screen.

I'm going to source a torq driver to open it up, and check for any obvious faults (Leaky caps + corroded battery )

I'm ok at fixing things (Well, I own analogue synths, which def comes with the territory) but any pointers would be great!

I'm guessing that this is a common problem (lots of posts relating to repairing mac classic II's) but to your experienced ears, does this sound like an power supply problem or something else?

Much regards

Mike