hoakley August 22, 2018 Macs, Technology

Apple changes SMC reset on T2 Macs, and updates NVRAM reset info

Apple has recently updated its support information on two important topics, resetting the SMC and the NVRAM.

Resetting the NVRAM – all Mac models

Apple has recently pointed out that, if your Mac has a firmware password set, you must turn that off before attempting to reset the NVRAM.

To do that, restart in Recovery mode, and in the Utilities menu, select either the Firmware Password Utility or Startup Security Utility. In that, turn the firmware password off, and shut your Mac down. You can then start it up with the Command, Option, P and R keys held ready to reset the NVRAM.

If you don’t turn a firmware password off and then try to reset the NVRAM, that reset will fail, and your Mac will probably enter Recovery mode instead. At least when there you can turn the password off, I suppose.

Resetting the SMC – Macs with T2 chips

Apple had previously detailed standard procedures for resetting the SMC of Macs with T2 chips, currently iMac Pro and MacBook Pro 2018 models. In case you have already forgotten, these are:

shut the Mac down.
once shut down, press and hold its Power button for 10 seconds.
after releasing the Power button, wait a few seconds, then press the Power button to start the Mac up.

(Apple has changed the period of time for which to hold the Power button from 8 to 10 seconds.)

It is now becoming clear that this doesn’t always work. In the event that that procedure fails to reset the SMC, Apple now recommends one of two procedures to be used as fallbacks.

For an iMac Pro:

Shut your Mac down.
Disconnect its mains power lead for 15 seconds.
Reconnect its mains power lead, and wait for 5 seconds.
Press the Power button to start it up.

For a MacBook Pro 2018:

Shut your Mac down.
Once it is shut down, press and hold the right Shift key, the left Option key, and the left Control key for 7 seconds. Then keep holding those keys while you also press and hold the Power button for another 7 seconds.
Release those keys and the Power button, and wait a few seconds before pressing the Power button to start it up again.

I have updated my article on resetting SMC and NVRAM to reflect these changes.

Apple takes pride in its superlative design. It is a great pity – and a pain for users – that this doesn’t now extend to the design of routine maintenance procedures. It is absurd there are now six quite different procedures for resetting the SMC, some involving keyboard gymnastics which many Mac users will at least find difficult.

It is also unacceptable that Apple has no means of alerting its customers to such significant changes in its documentation. It used to provide lists of recently added and updated support notes, but discontinued this practice some years ago. It should be reinstituted as a matter of urgency.

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1

Joss on August 22, 2018 at 9:41 am

On the 2018 MBP I’ve had erratic fan behavior after trying to manage fan speeds, first with iStat Menus, then with Macs Fan Control, so I reverted back to default system settings, but the fans kept running too high. Resetting the SMC with the default method (press power/TouchID button for 10 seconds) seems to have worked. The Mac did start up—the white Apple logo was briefly visible—, but it didn’t enter the actual FileVault preboot process, and switched off immediately again; I kept holding down the power/TouchID button for another 10 seconds from then on, and fans were fine again after boot & login.

Unrelated question: is there a way to change the screen resolution for single-user mode and for verbose boot mode? (Doesn’t seem like it.) The PreBoot & EFI resolutions are fine, the main boot resolution, however, is not.

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- 2
  
  hoakley on August 22, 2018 at 9:45 am
  
  Thanks.
  As far as I know, the display resolution for single-user and verbose boot modes are fixed, as they are determined early in the boot process. You might be able to set an NVRAM variable, but that would be very model-specific, if it worked at all.
  Howard.
  
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3

Manoli on August 23, 2018 at 6:50 am

Oh yeah, that’s true and sad, Apple documentation (including man pages) these days is incomplete, outdated, and for many things simply missing.

I still hope it will change, and we would be able to read again and understand exactly what’s going on in our systems.

Unfortunately sometimes even Apple’s own Support have no clue what’s going on when you contact them, because even for them there is no relevant source of information available. That’s sad.

Btw. for things above in this article, what I sometimes do, I use Terminal commands from Recovery mode:

pmset -a restoredefaults

as a “substitute” for SMC reset, and

nvram -c

for reseting nvram.

Seem it works and it does what is expected, but I don’t know if it is really same like ‘keyboard gymnastic’ (I like this expression) described by you in article above and I have no idea how it is related to iMac Pro and 2018 models with T2, how does it work if firmware password is set, etc. ?

Anyway, another great article, thanks Howard and keep up with great job.

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- 4
  
  hoakley on August 23, 2018 at 9:08 pm
  
  Thank you, Manoli.
  I think that the pmset command is strictly-speaking undocumented, but seems quite widely used. The nvram command is documented, and should do exactly the same as a regular reset.
  One neat way of doing these would be in Single-user Recovery mode (Command-s-r), which saves you from having to open Terminal. You could then just reboot and away – a good tip, thanks.
  Howard.
  
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- 5
  
  Joss on November 3, 2018 at 1:23 am
  
  This is actually the only thing that worked on my T2 MBP: Recovery Mode and `nvram -c` and `pmset restoredefaults`. Thank you for the info!
  
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6

tucpakic on August 26, 2018 at 3:28 pm

Correct me if I’m wrong but there’s no need to restart in Recovery Mode to tweak the Firmware Password. While in Normal mode, you can use the Terminal command ‘sudo firmwarepasswd’. Amongst options, use it with:
-check to check whether a firmware password is set or not
-delete to delete the firmware password
-setpasswd to set a firmware password
-verify to check if you still remember your firmware password. Bad luck if you don’t!

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- 7
  
  hoakley on August 26, 2018 at 3:32 pm
  
  Quite possibly, thank you. I only pass on here Apple’s recommendations as given in its support notes. Sometimes they avoid such shortcuts in order to avoid shell commands; sometimes they avoid them because Apple’s engineers consider that the commands could give rise to problems. Sadly, they don’t enter into such details very often.
  Howard.
  
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  - 8
    
    tucpakic on August 26, 2018 at 4:58 pm
    
    Fair enough, thanks.
    By the way, I suggest you add the status of the Firmware Password (enabled/disabled) in your LockRattler app. What do you think of that?
    
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    - 9
      
      hoakley on August 26, 2018 at 8:31 pm
      
      Thank you – it’s an excellent idea.
      I will try to build it into a new version in the next few days.
      Howard.
      
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- 10
  
  Joss on August 26, 2018 at 8:50 pm
  
  On older systems I used to just mount the Recovery Partition and copy the Firmware Password app to /Applications/Utilities … worked great. Now though it’s this new Secure Boot app, and it seems that it will only run when the Mac is booted into recovery. But the firmwarepasswd CLI should still do the trick.
  
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11

Sameh on October 31, 2018 at 4:16 pm

Does not work..
For some reason, my MBP 2018 with T2 is booting up during the process. Both combinations had been attempted.

Very confusing and frustrating at the same time

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- 12
  
  hoakley on October 31, 2018 at 4:18 pm
  
  Contact Apple Support; only they can help.
  Howard
  
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