Jon Anderson wrote:

I checked power to the drives. The 12vdc is
running 14v, but the 5vdc line is running a whopping 31 volts! I cycled
the input voltage selector several times, but made no difference. So,
new mobo and PS on the way thanks to eBay.
Impossible! If there was 31 V on the 5V supply to the drives, you'd
have flames pouring out of them! I have seen a DVM show 120 V DC
on a 5V supply where the equipment was working correctly. It may
be possible to turn off the auto-range and get a more reliable
reading. Or, try a different meter.

Jon