Did you find out about the hold down being a ground of sorts as mentioned above ? ?
No, i read it on another forum, but to me, it doesn't quite make sense as there are 4 hold down hooks in the motherboard. My heatsink uses 2 and there are 2 free. Looks like a different heatsink design may be used. Would the PC know what was used automatically?? I've never seen anything in BIOS to change which heatsink type is used........thought you guys might know.