I got an ASUS CUV4X-E mobo on ebay. The seller said the mobo was tested, but I am having doubts that the seller tested anything except the BIOS.
What happens when I try to boot any OS is the CD will spin up and say the generic message like "system is inspecting hardware..." and then the screen goes blank (but stays on) and just hangs. It does the same with all OSs I tried. Some of them actually display the OS logo at the beginning like TinyXP (which is my preferred OS), but then just hangs and doesn't even let me start the installation. It is clearly reading from the CD drive, but then something goes wrong right after.

It only boots very simple systems. The only thing that boots is memtest and it passes.
I tried replacing all the RAM.
I tried removing all cards except vid card.
I tired replacing IDE cable.
I checked master/slave jumper.
I tried another CD drive.
I tried removing everything except CPU, RAM, vid card, and CD drive (bare essentials).
I tried resetting the BIOS defaults.