iMac sign on corrupted

[douglasb7]

2021 iMac, fully updated. When signing on with admin it may or may not give us the desktop, but then just powers off. I feel that it is corrupted. I can sign on with guest, but have no access to any data, guest operates normally. I have performed all the first aid stuff. I’m not sure what to do to get the admin to sign on. Definitely not Hardware since guest works just fine so it must be something corrupted in the profile for the administrator. And then when it finally does give us the desktop it’ll sit for probably 30 to 45 seconds before shutting off again will not allow me to operate anything.

 

[niteflyr]

I'm not sure what "all the first aid stuff" means. Have you tried booting into safe mode? If admin works there it's probably one of the login items causing the problem.

 

[douglasb7]

I'm not sure what "all the first aid stuff" means. Have you tried booting into safe mode? If admin works there it's probably one of the login items causing the problem.

The first aid is in disk utilities. Said drive was fine. Same thing happens. I see safe mode upper right. But wallpaper and sign on name just get stuck right there. Nothing else happens. Mouse moves fine. Literally stuck on that page.

 

[Fishrrman]

Just wondering... do you have "non-administrative" accounts, as well (not including the "guest" account")...?

From what you have described above, it doesn't sound like either a hardware problem or an "OS problem".
Rather, it sounds like something wrong WITHIN your existing administrative user account.
This is why the "guest" account may still work ok.

What happens if you try this?

- Power down, all the way off
- Press AND HOLD the power on button. DO NOT LET GO!
- Keep holding it in for about 6 seconds and let go. If you see the screen display "loading startup options", you can let go a second or two sooner.
- You should in time see a screen showing you the internal drive (left) and another icon named "Options" on the right
- Click the "options" button, then click "continue".
- Let the recovery options load.

If you can get this far, then you know
- The hardware is probably ok
and
- The OS (at least the recovery copy) is ok.

What you could try here (a real "backdoor trick"):
Use terminal to delete the file
/var/db/.AppleSetupDone

WHY you want to do this:
The ".AppleSetupDone" file (which is invisible because of the "period" in the name) is created the very first time you set up the Mac with a user account. After it has been created, the Setup Assistant won't run again.
BUT... if you delete this file and reboot, it will [once again] open the Setup Assistant at boot.

WHAT TO DO NEXT:
It will "look like" the Mac is "brand-new", inviting you to create a new user account.
YES, you want to do this.
Doing so WILL NOT DELETE the existing user accounts -- it will only create a NEW one, "empty and clean".

Give this user account a special name and password (not the same as your "regular" user account).
It will exist "for test and recovery purposes" only.
You can delete it later when things are up-and-running again.

Once you have the new account (which will be an "administrative" account by default), now you can see if you can use the Mac normally -- that is, log in, get to the finder, open files, run apps, etc.

At this point, if the new account behaves "normally", as it should, now you have a working Mac again and from this point start working on "what went wrong" with the existing administrative account.

I -think- this is the proper "full" command in terminal to delete the AppleSetupDone file:
rm -i "/Volumes/Macintosh HD - Data/private/var/db/.AppleSetupDone"
(the quotation marks are included and part of the command)

If you have renamed the drive, you need to replace "Macintosh HD" with the new name.

WARNING WARNING
I'm not sure if the full command is correct.
I believe it is, but my "terminal fu" is not strong and I welcome correction from others.

Good luck.

 

[benholt]

The "signs on, sits for 30-45 seconds, then powers off" pattern is really specific — it's usually either a login item hitting a hard shutdown, or a scheduled power event that fires shortly after WindowServer starts. Guest works because it doesn't inherit either.

Two things worth trying from Recovery Terminal before the AppleSetupDone route:

pmset -g sched — that shows any scheduled shutdowns. If you see a repeating one that lines up with your login time, sudo pmset repeat cancel wipes it.

Then rename the admin's LaunchAgents so nothing auto-runs at next login:
mv "/Volumes/Macintosh HD - Data/Users/<adminuser>/Library/LaunchAgents" "/Volumes/Macintosh HD - Data/Users/<adminuser>/Library/LaunchAgents.disabled"

Also nuke ~/Library/Preferences/com.apple.loginwindow.plist for that user while you're in there. The fact that safe mode also freezes on the wallpaper points at a corrupted loginwindow prefs file — safe mode skips login items but still reads that plist.

If admin comes up clean after that, walk the LaunchAgents plists back in one at a time to find which one is triggering the shutdown. Beats blowing away the whole account and re-doing app licenses/sync/etc.

 

[Terraaustralis]

2021 iMac, fully updated. When signing on with admin it may or may not give us the desktop, but then just powers off. I feel that it is corrupted. I can sign on with guest, but have no access to any data, guest operates normally. I have performed all the first aid stuff. I’m not sure what to do to get the admin to sign on. Definitely not Hardware since guest works just fine so it must be something corrupted in the profile for the administrator. And then when it finally does give us the desktop it’ll sit for probably 30 to 45 seconds before shutting off again will not allow me to operate anything.

Tell us how you what worked for you Douglasb7

 

[douglasb7]

Ended up doing a full restore. Since we have iCloud, most was backed up. Computer probably needed it anyway! Ha!

 

[ignatius345]

Since we have iCloud, most was backed up.

iCloud is a good safety net, but definitely recommend doing full backups via Time Machine or another method like Carbon Copy Cloner. Since it's an iMac you can just tuck the backup drive behind the computer and forget about it until you need it.

 

[Terraaustralis]

Ended up doing a full restore. Since we have iCloud, most was backed up. Computer probably needed it anyway! Ha!

I was interested to see if Fishrrman’s suggestion worked for you. Otherwise my suggestion would be for a full reinstall from Recovery. I would also suggest keeping a duplicate OS on a separate drive or partition is a good plan to ensure you can boot into an OS for remedial work. I trashed Fusion, upgraded NVME to 4TB SN850x and upgraded SATA to 2TB Evo870 with identical systems on each drive. There is also a good argument for keeping the duplicate OS on external Drive. Depends on your approach. As you can imagine daily work is always on on the 850x which has 3 partitions.

Thanks for the response. An interesting problem from which we can all learn.

 

[douglasb7]

I was interested to see if Fishrrman’s suggestion worked for you. Otherwise my suggestion would be for a full reinstall from Recovery. I would also suggest keeping a duplicate OS on a separate drive or partition is a good plan to ensure you can boot into an OS for remedial work. I trashed Fusion, upgraded NVME to 4TB SN850x and upgraded SATA to 2TB Evo870 with identical systems on each drive. There is also a good argument for keeping the duplicate OS on external Drive. Depends on your approach. As you can imagine daily work is always on on the 850x which has 3 partitions.

Thanks for the response. An interesting problem from which we can all learn.

Thank you, sir for the good suggestions. We did a full restore, of course the computer is operating perfectly now, quicker now and all that good stuff. We do the iCloud backup. We do have an external drive. Normally just the documents/photos since my wife is a photographer get exported there but you’re right we should probably have a full OS just to get us up and running. I’ve been a Mac user since 97 never really seen this one before, just corrupted sign on for some reason but all is well. Thank you for reaching out.