Asus P4V8X-MX (or other Asus motherboard) won't power on

I've put this page online so that others with the same troubles may have an easier time finding a solution than I did. Obviously I have no affiliation with Asus, and all product names and company names mentioned on this page are probably trademarks of their respective owners.

Earlier this summer I needed to replace my Intel D865PERL that I got as a freebie with my Pentium 4 CPU. Basically, after years of mostly acceptable service, the PCI controller had become unstable, causing kernel panics when I tried to use my PCI ATA-RAID card and adding to my soundcard's output what can only be described as a “sizzling bacon symphony”.

As of 2007, socket 478 series motherboards and CPUs are almost extinct in the Canadian OEM channel, and I really didn't feel like buying a new processor when the processor was just fine. It took some hunting before I came upon a shop on College Street that sold the Asus P4V8X-MX. I'd had good experiences building Sempron-based machines with Asus K8N series motherboards, and so I thought I was in for a walk in the park. I got home, chucked my old crusty motherboard in the trash, seated the P4V8X-MX in its place and hooked it up.

Except it wouldn't turn on. Hitting the power switch would not yield so much as a fan spinning or a peripheral powering up, nevermind a BIOS screen or a beep.

I checked and rechecked every connection against the printed manual. I took the motherboard back to the store and exchanged it for another of the same make and model. When neither of these things yielded any results, I concluded that I must've somehow fried my power supply, so I bought a new one of those.

Finally after days of scouring forums, I came upon a post about another Asus motherboard that had severe errors in its manual. Namely, the diagram describing the pin layouts for the PANEL connector were completely wrong, and following that diagram you would wire the power and reset switches to the wrong place.

Both frustrated and hopeful, I sought out the online PDF version of the manual, and took a look at the diagram, comparing it to my own. I've posted the correct diagram here. This probably wouldn't have been a problem for someone who builds systems every day and knows the pin layouts by heart, but for someone who opens up his computer once every few months, it has the potential to be a serious headache.

Moral of the story: the user's manual cannot be trusted, at least with Asus products, but for a $40 motherboard, I guess quality documentation isn't of paramount concern. On the plus side I have had no other problems with the motherboard thus far.