What type of partition were you using at the time ? if you were using FAT32 for a 500gb for archiving purposes I see no reason for it to do that.
However if you used NTFS format which is for security and keepings things more managable, it may have gotten corrupted and locked itself up.
If your external hdd has software that came with it that might be able to reacess the hdd, give it another shot.
However if you used NTFS format which is for security and keepings things more managable, it may have gotten corrupted and locked itself up.
If your external hdd has software that came with it that might be able to reacess the hdd, give it another shot.