Sierra does not show mounted disks in Finder

I figured it out finally. Hope this helps some folks. When you get to the Finder Preference window shown in the screenshot from Lanny, click on "CDs, DVDs, and iPods" and it showed up. I've been trying to fix this for weeks and it was there where it shouldn't be of course, but it worked!

This solution worked for me - thanks! The "show/hide" does not appear until you mouseover. It overrides the preferences settings, but is otherwise invisible. If any devices are showing this probably doesn't apply, but if no devices are showing, it's likely to be the solution.

I tried all the suggestions on this page but this response was the only one that worked: On the sidebar, to the right of "Devices" is a teeny tiny ROLL-OVER OPTION you can't see until you...roll over it. Clicked "show" and all my externals came back. Thanks!

I am having this same issue.

Mac OS 10.12.3

13" Macbook Pro (latest gen with touch bar)

using USB C to USB adaptor

External drive is USB 3 and formatted OS X Extended (journaled)

External USB 3 hard drive does not show up on desktop or side bar. Appropriate boxes are checked in finder preferences for side bar and desktop. Drive shows up in disk utility. Temporary work around is right clicking the volume in disk utility and clicking "show in finder" so I can access my files, but this extra step is pretty annoying. I've tried repairing the volume (disk utility finds nothing wrong with it,) I've tried every USB C port, I've tried unmounting and remounting, I've tried rebooting. "Devices" are not "hidden" in side bar. Still no luck. Small USB flash drives show up. They are all formatted FAT32. Hope somebody finds a solution soon, or Apple fixes this in an update.

Solved. Although disk finder could find no errors on my external drive, I had to purchase another one, move all of my data to the new one, re-format the old one, and move my data back. It shows up fine now. Now I have an extra hard drive that I didn't need...

SOLVED for me! I couldn't see Seagate external hard drive in my finder. I had to go to Finder > Preferences and ensure CDs, DVDs and iPods was checked (and make sure Hard disks was a checkmark, though this wasn't the solution). For whatever reason, my external drive fell into this category!

I had this problem. Clicked and unclicked the "show in sidebar" options in Finder preferences, then relaunched Finder using the force-quit menu (alt-cmd-esc from Finder). The disks showed up again in the sidebar. Hope this helps.

ADS79 wrote:

Apologies but I'm not able to see this option in the SideBar. "Devices" has nothing to the right of it, but perhaps I'm looking in the wrong place. Appreciate any further guidance, thanks!

Nothing will show until you hover the cursor over that part of the sidebar. You should see either Show or Hide when you put the cursor over it.

Thanks, I had failed to hover before. When I hovered, it gave me the option "Hide", indicating that "Show" was already selected. I toggled back and forth between the two (ending on Show, of course), but it still didn't work that day.

A few days later I was working with external drives again, and now they're showing in Finder; don't know how it got fixed but all good now.

Same problem with NTFS drives. Previously I was able to read them, but since the upgrade I no long find them in finder. I found that if go into Disk Utility and locate the partition on disk, I can choose to open it in finder and it works. But still finder does not show the drive neither in device list, nor in my MacBook tab. Just to make sure - I checked the finder options, it's not that.

I'm having the same problem as well.

Once upon a time Apple was a good company with an exceptional OS, state of the art desktops that were relatively reasonable in cost and focused on the user experience. However that is no longer the case. They now offer 3 to 4 year old technology, a weak OS and sell phones. Mr. Jobs would be ashamed.

I know this might sound stupid and basic.

Did you try to open Finder and then on the Left Sidebar, hove your mouse on the slightly on the right of Devices and click on Show.

Hope this helps.

Somebody answered correctly but then I was looking in the wrong spot!

This seemed new to me, but beside the "Devices" "Show" shows up when your mouse hovers in that area.

Just check the option in the Finder's preferences: