Could it be that my degaussing wand isn't 'strong enough'?? I don't know much about them, mine is one of the Gamedude ones.
The machine itself has had the fucked monitor at the four different houses it's been located at, so it's nothing to do with it's current location... Although I only ever tried to degauss it here.
It really is driving me batty. I would go check the chasis for any issues but all the talk of high voltage etc has me a bit weary, to the point where I'm thinking I might just put up with a dodgy screen :(.
Thanks for all the help so far as well guys. Great community here :).