Asus P6T fails to detect SATA HD

Hello everyone

I built a new box at the start of the year and so far have had no hardware issues, up until the other day. I came home from work to find that my mobo was no longer recognizing that a HD was plugged in.

My BIOS shows only an ATAPI DVD rom plugged into SATA 1.

Trying to eliminate possible causes I tried the following:
- I checked the connections to verify nothing came loose, it all appeared ok.
- I checked the cables themselves by using the power cable and data cable hooked to the DVD, and that did not solve the problem
- I plugged into different SATA ports in order to confirm the port hadn't failed.
- At this point I figured it was the HD itself that had failed, so I purchased and hooked up a new one, but that didn't work either.

At this point I can think of these possible remaining scenarios:
- The original HD did fail, and the new HD was defective (unlikely)
- The mobo is broken in that it can't detect SATA HDs but can still detect SATA DVD (seems unusual)
- There is something wrong with my BIOS configuration

Any ideas on how to solve (or further diagnose) my problem would be appreciated!

is it plugged into the 2 orange ports or one of the 4 red ones?, if it's plugged into the organe ones it won't they're SAS drives (not quite sure what they are), try plugging it into one of the red ports instead. aside from that I don't know

no, it's plugged into one of the normal 'red' ports

Yeah I get the 'reboot and select proper boot device' message.
Is resetting CMOS the same as resetting the CMOS RTC RAM (which the manual describes)? If so, I will try it. If not, please let me know how to do so (or point me at a resource describing the process)

Thanks for the replies so far!

Ok, I'll try the CMOS thing tonight. I'll check if the HDD is actually spinning also.

Yeah I know this situation is possible so I'm not ruling it out completely. Unfortunately I don't have another machine/HDD at home to do the testing to verify the functionality of the two I'm working with.