Beeping MacBook on startup

My 2007 MacBook suddenly went dark. When I restarted it, I got the three chimes that indicate a RAM issue. I will try and reseat the RAM, but I don't think this is the problem, as I was using it and all was well. My questions:

1: Given the age of this MacBook, do you think the RAM has failed (at least one chip)? Or do you think the logic board may have gone? It does power up, but wont get to the Apple logo before it starts to beep. The power light blinks in time with the beeping.

2. How do I determine WHICH 2007 MacBook it is, if I decide to order new RAM? Since I cant boot it up (and no longer have the box), I don't have the serial number. Or is there one inside?

It is still adequate for what I use it for, so if it is simply a bad RAM module, I will get a new set. Advice?