It sounds like that SATA port may be dead.
The only other thing I can think of is to go into the BIOS and see if there is an option to discover drives. I have dealt with some BIOSes that required you to go in to the BIOS , have the BIOS 'find' the drive and then save changes to the BIOS. I haven't seen that in a long while, but heck it's worth a shot.
Otherwise, if the computer is under warranty then by all means take advantage of that.