FK90 wrote:. Rebooting gave me some strange lines in the screen.....
I hope they aren't the lines Im thinking of...
If it was me, I'd open it up. Take pictures of everything and start taking the machine apart, cleaning and reseating cables etc.. Remove all the expansions etc... I mean it should be clear by now your not gonna press a few buttons and it will fix whatever it is, but Im sure you know that. The spontaneity of the problem indicates to me it's a connectivity/cable/bent pin etc.. Good luck, hope you can keep another great machine from going belly up.
But I agree with debauch, it's really anyone's guess. Your at a point where you need to consider how you want to invest your time, fixing it or moving on...