New
#11
From the information you have given it certainly looks like a bad MoBo.
One last thing that came to mind:
If the 3rd drive (second SATA hard drive) has an operating system installed on it, or a partition marked "Active", then that has been known to cause Windows to ignore the drive. It usually does not affect the BIOS from recognizing the drive though. But, one last thing to check before pronouncing the MoBo dead.