USB External Hard Drive not showing up on Macbook

I have a Hitachi Touro USB 3.0 1TB external hard drive that has always worked on my Macbook. Formatted in FAT so it would work on both my PC and Mac. I can't remember exactly when it stopped working, but I think I had to reset my mac once as it stopped responding and the HDD was plugged in. After that it stopped showing up in Finder, but still appears in Disk Utility. It also shows up in Storage under "About This Mac".

Anyone have a solution? I've tried resetting my computer, ran Apple Hardware Test, and have tested the hard drive on other computers and it works fine. Just doesn't show up in Finder on my mac!!