Hi, I have 2 Macbooks (pre-unibody), both of which the same problematic symptoms. When either is turned on, the computer chimes and the screen flicks to a dark black. The fan begins to spin but there are no signs of hard drive activity. I've tried swapping out the memory and trying individual slots all to no availability. I know that this is not likely but could a dead PRAM battery cause this to happen? I've been reading about mixed thoughts on this and am hoping for a definite answer. Thanks in advance!