Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
I'd be very interested in the contents of that drive, as well as the model number of the box that it came out of, but the damage is done if you tried to format it, most likely.
There are a host of forensic tools that you can use to try to ressurect the filesystem, but if the box won't boot, there's not much point in the exercise. If / when you get to a point where the cable box works (or you have another specimen to go under the knife), feel free to use a livecd distribution to investigate. Plug the drive into a working board and boot off the cd. Use dd to copy off an image of the drive in question to "some other place" (another hard drive... be careful what you write where, or storage elsewhere in your network. netcat is very useful for things like this).
If you do end up with an image of a working drive, i'd be interested.