External hard drive won’t mount to MacBook pro
I connected an external hard drive to MacBook Pro to back up. I’ve been using them for years and never had problems. When I connect the external hard drive to MacBook Pro, it usually shows an icon and I can start back up but I don’t see the icon anymore. MacBook Pro is working fine and external hard drive is blinking and vibrating but not mounted. I tried Disk Utility, selected side bar “backup” and click “mount” but nothing. I click “First aid” but error message says “it’s failed and backup disk is not connected”.
I also turn off and on MacBook Pro. Disconnected and connected the external hard drive but no luck.
Please help.
MacBook Pro 13″, macOS 10.13