HELLLLLLLP

[daryl66]

Long story but will attempt to shorten it. Purchased a new Fantom external hard drive to back up  SWMBO's Mackbook air, OSX 10.15.5 and finally got it formatted  APFS, ran Super Duper which all seemed to be ok. Attempted to test the boot and it hung up about midway through the start-up. NOW I am completely locked out of her MB Air. Recovery mode shows a "sign-up" box which does nothing, no matter what I try I either get  a "folder" with a question mark in its midst  OR a Padlock. I think it is hung up with the back-up drive for whatever reason and I cannot get it to revert to the internal HD.

Daryl

[jchuzi]

My best guess is to do a forced shutdown by pressing and holding the Power key. Then, start up. Unless you changed the default startup disk, it should start from the internal.

If, on the other hand, you made the external the default, start up while pressing and holding Option until you see a choice of startup disks. Select the internal and press return. Then, reset the default startup disk.

If either of these is successful, we'll go from there.

EDIT: Did you, by any chance, set a firmware password by enabling FileVault?

[daryl66]

John:  Thank you.  After what seemed like a lifetime (swmbo) putting on the pressure. I finally found a link that explained that the "lock" required a "firmware" password was required to gain access to the recovery mode. Problem was I had not recorded it anyplace I could find, but thru hit and miss I stumbled across it. In the process now of reinstalling Catalina for her MBAir.  Will have to do more homework to find out what happened with the SD back up that caused it to lock out in the first place.

Daryl