My Passport for Mac reads, but won't write

My 1TB My Passport for Mac, about 1 year old, has stopped writing, but can read files stored on the drive, I have a new 2TB My Passport for backups, so I’d like to test the old one to see if it’s recoverable for anything. How should I do that? Mac Disk Utility just says it’s broken.

It would be helpful to provide the exact details related to the message displayed by Disk Utility. “Broken” can mean many things.

Have you tried formatting your hard drive?

Disk Utility just reports that both “erase” and “first aid” functions
failed. Clicking on details doesn’t reveal anything I can interpret or act
on. I can read the files on the Passport, but I can’t copy, move, or erase
them, and I can’t write anything new on it.

Does Disk Utility error report suggest you “Invalid B-tree node problem” or other such error displayed in red colour? If you have a backup of this disk, then you can erase it using Terminal. Here is a helpful link for erasing the WD with Terminal command lines http://smallbusiness.chron.com/format-os-x-terminal-hard-disk-57815.html Also see this link where some more cryptic disk errors have been mentioned. You might recognise one such error with that suggested by the Disk utility. http://www.macintosh-data-recovery.com/repair-mac-drive.php