I am posting from my 770 at work, so this will be fast, (more to come later) I see on the ribbon cable/pcb, that there is a 8pin sdip chip. Can you get the number from that for me? Looking at this I would say that that is probably NOT the controller. But I would like to check it out, I expected a chip with alot more pins than that.
Has anyone tried to swap a WSOD screen sub assembly with a good one?

Because just a guess, but the chip may be under the metal housing behind the illumination panel. See how there is a separate ribbon going into the housing on the left? That would be for the CFL inverter assy, so if they have the inverter inside, it would stand to reason that the controller could be inside as well.
any chance of further dis-assembly?
-ezra