In the interest of clarity, that is a 512ke as opposed to a 512k. Nice find!
Is the screen dark? As in, if you turn the brightness way up, you still see no glow at all? If so, whack the left side of the case. Does it flicker the dark monitor at all? If it does, you probably just have a dry solder joint on J1 of the analog board. Try refreshing the solder on it and the larger connection to the Logic Board.
The drives whirring non-stop can sometimes indicate bad bourses filters on the Logic Board.