Ok since I've been on holiday and stuff I haven't had much time to try and fix this, and now the problems get weirder and weirder... I bought a new power supply, 580W, had all the right cables and stuff, but still it didn't work.. when I unplugged the graphics card the motherboard and fans start up, bit it emits a constant, loud, high-pitched eeeeeeeee noise. Thing is though, that happens as well with my old power supply, so I didn't need to get a new one after all. So the mobo starts up with the GFX card unplugged, but if I physically take out the graphics card it doesn't start up at all. I have no idea what this high-pitched noise means... in the manual it doesn't say what it could be, only for 4 short beeps and stuff like that. Anyone got any ideas? Sort of getting desperate now... going to Uni on Tuesday which I kind of need it for.