I have the same issue with a 1.5 TB Seagate Free Agent Desk that I use.
Before checking here, I was made to believe that it was possible (though unlikely, then maybe more likely) that the issue could be fixed with a PCB swap. Opening the external shell, I found a Seagate Barracuda LP. Going to the same store the original was purchased, I bought an internal Barracuda and another Free Agent. The Internal appeared identical save for the firmware code (CC34 versus the original’s CC94), but the drive from the external shared even the firmware. Switching first the internal then the external, it sounded as though the drive was getting power, but the computer was having limited success in recognizing it.
So I check here and see the options are to remove the TVS diode and/or to swap the EEPROM along with the PCB. I intend to try the former first (unless the latter is a better overall solution), and the latter if that doesn’t work, but have a few questions.
First, here is an image of the PCB; I have circled in red what I believe is the diode as to all appearances that is what was fried (there is very little evidence on the board itself, but the padding between the board and the drive had been burned into the shape of that component).
My initial question contains three parts: is that circled part the correct diode? Would I only remove that? Is it mandatory that it be desoldered for removal (the drive’s owner is considering forcing the component out, he does not currently have the equipment to check the ohms nor to remove the solder)?
The second question is which piece is the EEPROM?
Whoever might answer, thank you.
Order this pcb online: Seagate PCB 100535537