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External Disks Appear As Grey Boxes in Finder...


macrumors newbie
Original poster
Nov 21, 2016
TLDR: Determined refurbished 16" MBP has bad/failing USB C ports on one side after extensive troubleshooting. Having a back up/recovery plan was the difference between a significant inconvenience and a catastrophe.

Background: 10.15.3 Time machine backup of a 2016 15” MBP installed on a 2019 BTO refurb shipped with 10.15.2 and upgraded to 10.15.4 AFTER setup migration assistant.

Problem: External HDs function fine (read/write) when connected with Apple dongle/Belkin TB3 cable. However, their icons in Finder appear to be missing or corrupt. The icons appeared for the first week or so, then they started turning to grey boxes.

At first the TM and external drive icons would appear as normal when connected, then they would start out fine after a reboot but turn to grey squares upon opening subsequent Finder windows, and eventually they would turn grey immediately. Also tried a random thumb drive- they all do the same thing. Drives are Samsung T3 and WD Passport. Icons appear on desktop, DU, NTFS for Mac, and Commander One correctly.

What I’ve done:
0. Performed PRAM/SMC resets.
1. CMD R, reinstalled MACOS while retaining existing user account; problem returned.
2. Created an account called “test”; problem resolved for the 12 hours the account existed.
3. Used test account to delete real account but chose the “save home folder” option. Created another “real“ account with same name to assume the home folder of the deleted account. Logged back into the newly created “old” account and deleted test; problem returned.
4. Deleted account made in step 3 and created a different brand new account. I used migration assistant to migrate “computer/network settings”, “other files and folders”, and “applications”, and manually migrated personal files, but NOT the user account; I now have permission issues and icon problem returned.
5. Did another TM backup, CMD R again, reset permissions in terminal, and reinstalled Catalina; problem returned.
6. Tested external drives in my son’s 2019 13” MBP; problem resolved.
7. Now have disappearing iMessages after I manually transferred the files and icon problem persists- updated Samsung firmware, ran DU first aid on each external drive, reformatted boot drive and reinstalled Catalina. Performed TM recovery of only the “applications” folder of the account created in step 3; problem resolved until I connected two drives on the same side of the MacBook, one of them was a different known good thumb drive. Finder icons immediately turned to grey boxes and have not returned.

Where I am:
*Due to problem not occurring on a different MBP with the same HDs connected at the same time/side, a nuked boot drive and "application" only TM restore exhibiting normal behavior while drives connected to different sides of the laptop, I'm led to believe it's a hardware issue with left side of my MB and not an application or corrupt user account causing it. I'm now up and running, but will be exchanging this machine.

Lessons Learned:
*With iMessage history officially in the cloud, I found there was no need to manually migrate the iMessages folder. I simply opened the app this third time around and it's been downloading since. I was sure to delete old devices from Apple account and disable/delete/re-enable text message forwarding for the Mac on the iPhone.

*After third full account setup, was forced to purchase Office 2019 standalone after losing the ability to reinstall my 2016 copy (apps were grey/ X'd out in finder). I really like the new Outlook so I'm glad that happened.

*Lost a lot of time/productivity but didn't lose any data because I was one-way auto synching critical folders with Synch Folders Pro+ and performing TM backups at stable points throughout ordeal. Back up, back up, back up.

*edit* Documented for internet posterity, Googling the problem and getting my own post as a result was hilarious.

Same HDs different Macs


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