M17x R2 won't boot ( GPU problems )

Let me start from he beginning, this laptop has give me a few problems but they were all resolved when I called dell and had them replace my motherboard. With this new other board everything was fine up until one of my gpu fans had started making a very annoying rattle at which point I opened my system up, cleaned out ALOT of dust and went on my merry way. a week later, the fan starts making the noise again right before I go to bed, I think nothing of it as my Easter break starts tomorrow and I will have a week to work on it. Well, that morning I turned my computer on and amazing,b,us squares all over my screen. I google it and it sounds like a gpu problem so I turn it off and head to school. I come back turn my computer on and ow my LCD isn't turning in, but my external monitor works and shows as it boots many blue lines that are vertical and as it booted they turned into blue squares that cover the whole screen. So I ring up dell and they tell me it'll be a few hundred to renew my warranty and have them fix it and I would pay for parts. Seeing asi don't have the $$ for that right now, I decide to buy a new gtx580m to replace my 4870HDs in crossfire. Well, when it arrives I pop on my gtx580 everything sounds good but my screen remains black, no beeping its as if everything is running properly I just can't see anything and I'm not sure what to do, I need to see :( got work to do p.s. ( I did clean tummy old ATI drivers) and I replaced the indicator cover cable( thing that leads power button to motherboard) as it was damaged when I went to clean the dust out. I hope you guys can help me,I know the 580ms aren't supported, but I've seen a lot of testa movies where it works seamlessly.