MacBook :: Unibody Unexpectedly Shut Down / Won't Turn On

I have an aluminum macbook with a 2.4Ghz core 2 duo processor. I am the second owner, but I have owned it for about a year and taken good care of it. The other day I was browsing the internet internet and my macbook just turned off. It didnt give any warning or go through a shutdown sequence, it cut the power and turned off all of a sudden. I should tell you that it has done this once before, about a week ago. However, in that case I was able to turn it right back on without any issues. Now, on the other hand, I cannot get it to do anything. No chime, no gray screen. All that happens is the little white light on the lower right side flashes for a brief second. There is no screen activity, and as far as I can tell by holding my ear up to the hard drive it does not start to spin at all. I have attempted to reset the pram and smc, but I have no idea if it is resetting. It was not hot at all when it shut down, it had been sleeping and I had only just started using it. It was still cool to the touch on the case. Does anybody have any idea what could be causing this? I do not have the money to replace the logic board, so I am hoping it is something else.