WD My Passport for Mac 2018 Portable External Hard Drive - USB 3.0 Review & Vs Old Version WD My Passport for Mac 1TB WD My Passport f. The WD Passport Ultra was plugged into my MacBook on battery. I was not actively reading or writing to the external hard drive, but it did have a list of Ever since that my WD hard drive has the flashing problem and can't be mounted on my Mac. I tried changing the Mac laptop, changing the USB cord.
SOLUTION Go to Control Panel / System / Harware / Device Manager / slide down to the list at Universal Serial Bus Controllers, you will find a USB Mass Storage Device with a yellow triangle. This is your external Drive controller that failed to initialize and will always remain like this even after reboot. Until you right click Uninstall and when done, just right click on any of the devices in the list, (or in the Actions menu above) select scan for hardware changes.and voila! Your external USB Drive will be regognized and start functioning as it should. This applies to WD passport USB external Drives as well.