[Bungleau]

If he tried combining memory from one computer to another, it may well be that the memory isn't compatible, and that's causing a problem. I'd remove all but one stick of memory and try to boot with that. If it succeeds, look for a similar stick and boot with that. Repeat until you've identified which are the new ones and which are the old, and then put 'em both back where they belong.

I first ran into that problem with memory for my first home-built machine. I didn't realize that the motherboard couldn't handle anything greater than 66Mhz memory; the 100Mhz which was standard on the street wouldn't be recognized. I eventually used it in my second home-built machine, but it was a waste of time and money until then.