This issue is quite common for external hard drives hooked up to the Wii U which have a USB 3.0 interface and hookup. This stems from a problem with the Wii U's individual USB ports not providing enough power to a USB 3.0 external drive. Flash drives, USB 2.0 drives, and externally powered USB 3.0 drives seem to work, but not portable USB 3.0 drives. How do we fix this? WE NEED MORE POWER!!!!! It will run you back a few dollars, but this fix is quite cheap and will let you easily fully power your drive from your Wii U alone!
Be warned though - This isn't some magical fix which will revive any clicking drive. By watching this video, I assume that you have a perfectly working hard drive which is running fine on your computer but clicks when connecting it to a Wii U console. If that is the issue you're having, this guide will do the job!
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