I used this fantastic guide to fix ye olde Mac Pro. Actually, I used this guide twice… the first fix to realize that I Mac Pro won't startup, I suspect the Northbridge chip on one Mac Pro, then using my backup Mac Pro to resurrect the Mac Pro I needed. I decided to do this to the healthy board since they were both the same age and had lasted this long… I didn’t want to risk another failed piece of plastic. I’d like to actually contribute to this guide by saying that I used M3x14 instead of M3x16 screws and did NOT have to drill out a hole. It’s a tight fit, but I built a rig to hold up the board so I could get my hands under it and hold the nuts while I screwed. Ha ha.