Computer Surgery

So even as I write this I live in fear that my machine could crash and turn itself off at any moment.  I pulled it apart as far as I could yesterday and blew it out really good with some canned air.  It worked great all day and never shut down once.  Today I wake up to find that it had shut down sometime in the middle of the night.  I try to reboot and it shuts itself off again before even getting to the blue windows screen.  I’ve tried blowing it out again, but this doesn’t seem to be fixing my problem.  Now it looks like I may have to actually take it somewhere to get it fixed.  The warranty was over like 2 years ago too.  I think I’d better start saving up for that Macbook Pro.