Can I Set SU (root) Password in Single User Mode? (10.11.6)

Question

Level 1

8 points

Can I Set SU (root) Password in Single User Mode? (10.11.6)

17” MBP will no longer boots OS X, most likely due to GPU failure. Need su (root) privileges to move AMD kext file in hopes MBP will bypass failed AMD GPU and run with Intel GPU. Administrative privileges result in permission denied messages when I attempt mkdir or mv anywhere in the /System directory tree. I’m the original owner. To my knowledge the root password has never been set. Attempts to enable su with blank root password result in “Sorry”.

Thanks

MacBook Pro 17", OS X 10.11

Posted on May 15, 2020 9:20 AM

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Answer 1

HWTech

Level 9

69,254 points

May 15, 2020 2:19 PM in response to Dougrc

Are you booting in Single User Mode or Recovery Mode? You may first need to disable SIP security using:

csrutil  disable

while booted into Recovery Mode. Just remember to re-enable SIP afterwards by running:

csrutil  enable

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Answer 2

May 15, 2020 3:23 PM in response to Dougrc

Here is a comprehensive recipe for what you need to accomplish. You will get your display back again, using only the Integrated graphics:

http://dosdude1.com/gpudisable

You will lose:

ability to change screen brightness

system sleep (screen sleep will still work)

ability to connect an external display.

do not attempt to use this unless you are willing to accept the risks involved: your computer will not work the same way afterward (since its already not working, that may not be much of a problem).

This disclaimer is added to protect the innocent, in hopes that the hosts do not remove this post for being potentially damaging.

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Answer 3

May 15, 2020 5:55 PM in response to Dougrc

Try an SMC reset and see if it calms down. (not a PRAM reset if you used dosdude's nvram patch).

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Answer 4

May 16, 2020 6:58 AM in response to Dougrc

Some swear by adding this nvram command:

sudo pmset -a gpuswitch 0

pmset is the power manager settings, but there is no easily-found documentation for this specific setting.

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Answer 5

Dougrc Author

Level 1

8 points

May 15, 2020 5:42 PM in response to Grant Bennet-Alder

I already performed the method that involved moving the AMD kext file out of the Extensions folder. I got SIP properly disabled with HWTech’s help then everything worked. I enabled SIP. Power on looks to be starting single user mode. After login, more of what looks like single user mode except it goes from that to a white screen, then the startup chime and finally back to the login window. Login again and it repeats the cycle. Maybe there are more problems with the MBP than just the GPU. It does get quite hot during this process. I did not attempt any of the GPU thermal/power fix yet. I’ve got nothing to lose as long as I can get the SSD drive out of it before it goes up in smoke! :-). It’s only a matter of time before I go get a new 16” MBP to replace this old guy.

Thanks!

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