I'm hoping someone can provide a solution for this.
I have a FAP 750GB USB/FW400/eSATA drive. Since the drive wasn't recognized on my Mac over eSATA, I contacted support and they provided me the firmware update. I successfully applied the firmware update from a Windows machine through USB - everything was done as per the instructions given and I'm 100% sure I applied the right firmware - at least the one that was provided and matched the one already in the drive except for the version number. The moment the firmware update finished, the drive powered down and has since not been powering on when connected through USB or eSATA. Before the update, the drive worked well with USB and FW400, and just powered on with eSATA (without being recognized as a drive).
Now the drive powers on and works when I switch the interface module to FW400 and connect it via FireWire. I have tried two different USB cables (that work well) and three different computers (two Compaq laptops running Windows XP Pro SP2 and one Mac running Mac OS X 10.4.11), but haven't seen it work yet over USB. Seagate tech support doesn't have a solution for this issue right now.
If anyone has noticed this problem (either with or without the firmware update) and has any suggestions or advice that doesn't involve moving the drive to another enclosure, please let me know. If Seagate cannot replace this drive or resolve this, I would be willing to open up the enclosure for any "surgery" required. I spent a lot of money on this drive thinking that eSATA would be much better so not having FW800 didn't seem like an issue when I bought it.
I'm experiencing a similiar issue with my 500gb desktop model. I brought it to work with me so i could re-arrange the many files i had. Since leaving work and coming home, it does not power on. I checked the adapter with another device, it works fine. I tried the 500gbdesk on my laptop as well still no light/windows does not recognize the drive. I know i don't want to loose all of that information. I know i may indeed need to open it, and transfer my data i suppose.
I'm sorry i'm not help, hopfeully someone can help us!!!