I did a search on the drive model when my son's Seagate 750 went toes up, did a lot of patience googles and found an known problem with firmware. It took some careful and polite email back and forth to Seagate but they recovered the drive and data at no cost to me other than "maybe" one way shipping, but I think they actually mailed me a shipper.
I also found a bunch of places that would "help" me guaranteed for price, but that help varied from expert and expensive to idiot shorting pins with tin foil and still not very cheap. Someplace in the middle were the guys swapping boards or using other methods to update the firmware.