How to reset the SMC, PRAM and NVRAM on an iMac Pro

简介

I had to make a separate guide for this Mac as this Mac has the new T2 chip and requires a different procedure then the other Mac Desktops.

步骤 1 SMC reset Part 1

How to reset the SMC, PRAM and NVRAM on an iMac Pro, SMC reset Part 1: 步骤 1 中的图像 1，1

Choose Apple menu > Shut Down.
After your Mac shuts down, press and hold its power button for 10 seconds.
Release the power button, then wait a few seconds.
Press the power button again to turn on your Mac.
If that did not solve the issue, move on to Step 2

编辑

After the iMac Pro shut down, I pressed and held the power button for 10 seconds. It began to power up so this didn’t seem to work.

C Adams - 2018年11月4日回复

What is the problem you are trying to solve by attempting to do these resets?

[deleted] - 2018年11月4日

步骤 2 SMC Reset Part 2

How to reset the SMC, PRAM and NVRAM on an iMac Pro, SMC Reset Part 2: 步骤 2 中的图像 1，1

Choose Apple menu > Shut Down.
After your Mac shuts down, unplug the power cord.
Wait 15 seconds.
Plug the power cord back in.
Wait 5 seconds, then press the power button again to turn on your Mac.

编辑

步骤 3 PRAM and NVRAM reset

How to reset the SMC, PRAM and NVRAM on an iMac Pro, PRAM and NVRAM reset: 步骤 3 中的图像 1，1

Shut down your Mac.
Then turn it on and immediately press and hold these four keys together: Option, Command, P, and R.
You can release the keys after about 20 seconds, during which your Mac might appear to restart.
You can release the keys after the Apple logo appears and disappears for the second time.
You must have a wired keyboard made by Apple in order for this to work.
You can buy one from Amazon here.

编辑

I have never been able to do a PRAM reset on my iMac Pro. I even got the stock extended wireless keyboard out of the box to try to do it, and never get the satisfying triple gong of yore.

C Adams - 2018年11月4日回复

It needs to be a wired keyboard made by Apple, not a wireless keyboard.

[deleted] - 2018年11月4日

Hello C Adams, it is very true I share Aaron's grip, you have to use an Original Apple keyboard with cable to be able to restart the SMC + PRAM + and + NVRAM, and any on the iMac or any Mac, greetings

Miguel - 2018年11月5日

it worked! and, if you want your startup sound back on the iMac Pro, use this terminal command:

sudo nvram StartupMute=%00

Admin User - 2020年3月27日回复

You don’t have to shut down the computer; restarting works just as well. Just ensure the four keys are down as soon as possible after the screen goes dark.

A wireless keyboard connected with a Lightning-to-USB cable permits parameter RAM reset. You don’t have to buy a new wired keyboard.

trudyscousin - 2021年2月22日回复

Command-Option-P-R works with a wireless keyboard wired with the lightning cable (the one coming with the iMac Pro); however do not shutdown the Mac first.

Boot the Mac, restart it. As the screen goes black and before the Apple logo shows, press Command-Option-P-R and hold it ; the screen will stay blank and then after about 20s the apple logo will appear and the dong will be heard. Keep pressing Command-Option-P-R until the logo disappear and re-appear a 2nd time with the dong sound

jyavenard - 2021年8月17日回复