What should you do in this circumstance? What are the effective solutions to make your USB drive show up again? Though not a usual thing, the issue of an external hard drive or flash drive not showing up on Mac happens sometimes. Did you come across the situation that no matter how many times you try to connect the USB drive with a Mac computer, the USB drive is not showing up anywhere? Why this time Mac won't recognize a connected USB you may wonder. Mac Won't Recognize USB, What Should You Do?Ĭommonly, when you insert a USB drive in the USB port on a Mac computer, the drive will soon appear on the desktop or hide in the Finder, letting you access, view, and manage data on it.