I accidently plugged in the power cable of my laptop into my Seagate external hard disk drive, 1TB. That is 19.5V, 6.15A in place of 12V, 1.5A. Now the drive does not show up. Obviously I blew up something and I'm gonna take it to the specialist tomorrow. Just dying to know what must have happened to the data? Is the hdd as good as dead? or could it be just the enclosure that I blew up? Any probability at all of recovering data?
Your data is probably still intact. In the first instance I would take the HDD out of the enclosure and try connecting it up inside a desktop PC via SATA and a power connector.
If it still does not power then you have bigger problems. Some people have the skills to swap the electronics on the HDD if you can find an identical drive as a donor or you can send the drive to a data recovery specialist but that's pretty expensive.