This is my case:
I was watching a movie stored on my Seagate Barracuda 7200.8 External HD then i had a power failure in my house and everything turned off.. When i tried to turn on my HD again it made an unusual ticking sound like every second or so, the computer made the usual "usb device plugged in" sound but there was no drive and it wasn't reading it. I tried like 5 times and everything was the same.
I'd like to know if its completely damaged and all data was lost, or how to know that, or if its still there how to recover it.
I am really sad because I have like 180 GB of important data and personal stuff that i cannot replace. So if any one knows a solution please help me!
There's no way to really know what the state of the drive or the data is until you look at it with a dedicated recovery tool.
If it was my drive, I would remove the drive from the USB external case, mount it in a machine as an internal drive, and run GetDataBack for NTFS.
GetDataBack might take forever to scan the drive, but it will usually recover data if anything on the drive is readable.
From the failure mode you describe (power surge), it's unlikely that the drive is damaged internally (platters/heads), except perhaps a certain small range of sectors that were overwritten during the surge. A far more likely scenario is that the logic board on the drive is fried. If that's the case, a swap of the logic board with one from an identical drive should at least allow GetDataBack to run and recover some data.
Of course, there's no guarantees, and anything you do to the drive will at a minimum void the warranty, and possibly make the data harder to eventually recover.