The most common answer to such a SATA problem is definitely the data cable. They don't fasten securely to the drive and can work loose.
After having that problem with mine, more times than I want to admit to, I finally HOT Glued the connector to the drive. That put an end to that problem, once and for all.
Now, I HOT Glue every data cable to every SATA drive I install.
You also need to check the power cable. Check every connection all the way back to the power supply.
They also DO fail. I've RMA'd several SATA drives in the past year. Most were WD but one was a Maxtor.
I suspect they all fell subject to heat exhaustion.
Good Luck,
The Shadow
