Hi abraxela,
I'm afraid you are in a wrong place. This is a place for software development. Your issue is not related with development.
Putting that aside....
According to your description, your external HDD would be corrupted.
If it is corrupted, no software can recognize it (with no response). Can you hear rotating sound of HDD? Can you see access lamp lit or blinking? If you connect it to other computers, how about it?
Regards,
Ashidacchi