Unibody Macbook Stuck on Apple Logo
Apple geniuses have a lot of latitude with what they can do. I have gotten a motherboard replacement about 2 weeks after my 3 year Apple Care plan expired. If you go to the store and are honest you could get lucky. I haven't heard of anybody getting service after a month. At the least the genius can tell you for sure what the problem is.

So make a genius bar appointment and see what they say. With Apple it really doesn't hurt to ask.