I would like to know how to recover data from an unreadable external hard disk as the external hard disk cannot detect and read. Thanks
If hard drive is undected, then it means it's dead. You may have to get a new one.
Not necessarily. It may be dead but it could also just be wounded. I have recovered data from drives of all sort that did not show up in windows by first checking if linux sees them and if not then I run testdisk from linux to find out if it sees them. Sometimes even linux doesn't see a drive but testdisk does. If testdisk doesn't then I call the morgue but not before.