MacBook won't boot, no chime, solid white LED, black screen?

I have a 2007 macbook core 2 duo 2Ghz that does not boot. I just get the solid white LED with no chime and a blank screen. The MagSafe plug is green, I have fan and hard drive power and I also have power to the left board for USB sockets etc. I've been reading a lot of forums on this topic and I'm concluding I have a logic board fault as I've tried everything such as reseating ram, resetting smc/pram etc. I've tried cleaning the board with isopropyl to no avail. My final attempt was going to be to bake the board which I've read about. What I'm wondering is has anyone had this issue and if so were you able to identify what it was on the actual board that was causing the issue? I've read that a gpu failure can cause this if you have the nvidia chip which I don't but other than that I've not come across a particular board component for my model which stops it booting. Thanks