Secret Mac reset options to fix problems that won't go away

Posted: April 17, 2015

There are special keys you can hold down when the Mac starts up to fix a variety of strange problems with Apple's desktop and laptop computers. If you have tried everything else and problems persist, try these tricks.

PRAM and NVRAM on the Mac

The Apple Mac has a small amount of special memory that it uses to store a variety of important system settings. On old Macs it is called PRAM, which stands for Parameter RAM, but on recent Macs it is called NVRAM (Non-Volatile RAM). Basically, it is memory that retains its contents eben when the power is switched off.

For some unknown reason the contents of this memory can become corrupted or it might contain faulty settings and this can affect the running of the computer.

NVRAM or PRAM is used to store information like the speaker volume so that it is set at the same level next time you power on. It stores the name/location of the startup disk in case you have two or more drives, or partitions with Bootcamp and so on. It remembers the screen resolution so it can restart with the same settings, and more.

Any problems you are having with these components, and a few more, could be caused by corrupt NVRAM or PRAM and may be fixed by clearing it and started with a clean slate.

MacBook Pro

Reset the PRAM or NVRAM on the Mac

To do this, turn up the volume to the maximum, then power off your Mac. Press the power button and straight away press and hold the Command, Option, P and R keys before the grey screen appears. The Mac will begin to start up and you will hear the startup sound. Keep holding those keys until it restarts and a second startup sound is heard. Let go of those keys and let the Mac boot up.

After resetting the NVRAM/PRAM, you might need to open System Settings and select the startup disk, screen resolution, time, and sound if the defaults are not to your liking.

Reset the SMC

The NVRAM/PRAM is not the only component that stores system settings and there is another called the SMC, short for System Management Controller. This performs a lot of functions and among them is the system fan, if your Mac has one. If the fan is blowing all the time then resetting the SMC can help.

The SMC controls all the lights, like the keyboard backlight, the status indicator, battery indicator, and display backlight. It controls the power, including the power button, battery charging, sleep mode, opening and closing the lid. It controls the CPU, which affects the system performance, the bounce of Dock icons, video mode switching and more.

Resetting the SMC should be done as a last resort when you have tried everything else and it has failed to solve the problem you are having. It is not the first thing to try because it has such wide-ranging effects on the system.

On a MacBook with no removable battery, which is pretty much all Macs in the last few years, plug in the mains power and shut down the computer. Press left-Shift+Ctrl+Option and the power button all at the same time. Release all of the buttons and then switch on with the power button in the usual way.

An old MacBook with a removable battery is different and you must shut down, unplug the power and remove the battery. Press and hold down the power button for five seconds, then release. Put the battery back in, plug the power back in and start the MacBook in the usual way.

The iMac and Mac mini are different again. Shut down the Mac and unplug the power cable. Wait 15 seconds and plug the power cable back in. Five seconds later, press the power button to turn on the Mac. The timing is probably important, so have your watch, an Apple Watch of course, next to you when you do this.

Author:

Roland Wadddilove

Tags:

Hardware

How-To

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Comments

Submitted by doreet (not verified) on Tue, 01/05/2016 - 09:17

MY SISTER HAS APPLE OWNERS,TELL HER"APPLE NEVER HAS PROBLEMS,"

"APPLES NEVER HAVE PROBLEMS, ONLY PCS HAVE PROBLEMS." THESE apple users.tell her,"get an apple, you'll have no problems any ,more, with anything."they are LYiNG AND BRAGGING.WHERE IS A GOOD HONEST CRITIQUE OF AN APPLE, YOU BUY?--I think apple has issues,too,just different ones.but they are telling her"apples never have any problems."BS! WHO & WHERE, ONLINE, CAN I REFER HER TO? THANKS!---who can tell her the real apple truth? thanks again. :)

Submitted by rwaddilove on Tue, 01/05/2016 - 10:21

Apple Macs have problems too

It is wrong to say that problems never occur with Apple Macs. They do. For various reasons, there are fewer viruses and other types of malware for the Mac than for Windows. This alone means that Mac users tend to have fewer problems. It is an advantage Macs have over PCs. There are hundreds of different types of PCs and the quality varies from poor to excellent. If you are knowledgeable, you can find great PCs, but some people aren't and they buy a cheap PC and regret it. All Macs are good, but then Apple doesn't make cheap Macs. It only makes high quality products for which you pay top prices. I use Windows PCs and rarely have any problems. I also have a Mac and rarely have problems. So which is best? They are different and I like both. I use a Mac in the mornings and a Windows PC in the afternoons. I have no preference.

Submitted by michaela (not verified) on Mon, 08/21/2017 - 04:02

unable to log in after PRAM reset

I was having a problem with a pointer so after installing latest system updates with no effect on crazy pointer, I did a PRAM reset. From then on, a log in page has changed: my user name has changed (in past i was using my whole name as login name. Some months ago, I changed it for a 'nickname'. But now, after PRAM reset, the old/previous user account name appears. there was another account 'guest' not secured by password. Now the password is required. 'my account' with changed user name doesn't accept my valid password. When typing a password incorrectly for 3 times, there is pop-up to log in with my apple ID. That does not work either. The password is correct. I am using this: MacBook Pro 2011 late latest operating system with updates I never changed my apple ID since created changed my Apple ID last year changed my computer password also about a year ago

Submitted by rwaddilove on Mon, 08/21/2017 - 07:38

Login problems

I would check that you can log into to appleid.apple.com using another computer. This will check that your username and password is valid. If you can do this, try logging into your Mac again. After 3 failed logins you should be able to use your Apple ID. An alternative is to try this: Start in Recovery Mode by holding down Command+R when starting up. Select Disk Utility, open Terminal and enter 'resetpassword'. Select the drive and the account. Enter a new password.

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