How to Reset Mac’s NVRAM, PRAM, and SMC
When your Mac system starts showing issues, you can start basic troubleshooting to fix common issues. There could be lots of problems including Bluetooth not connecting, AirPort not working, Mac doesn’t charge, performance issues and more. If you are not sure what’s wrong with your system, you can perform basic troubleshooting steps.
You can try resetting PRAM and SMC. Before you do that, make sure you have removed all drives, speakers, external display and keyboards from the system.
How to Reset PRAM or NVRAM
Mac system contains a small amount of special memory called NVRAM (Non-Volatile RAM) or PRAM (Parameter RAM). Both stores settings used by Mac system to control the configuration of the system.
Steps to reset PRAM and NVRAM are same in older systems. Here is how you can reset PRAM and NVRAM of your Mac system.
Shut down the system. Press the power button, as soon as you hear the startup chime, hold down Command-Option-P-R and keep holding these buttons until you hear a second startup chime. The allow system to continue starting normally. The check the Startup Disk, Display, and Date & Time panes of System Preferences make sure everything is fine.
Reset the NVRAM on Newer system (2016 MacBook Pros and Later)
In newer models, steps for resetting the NVRAM is different. Follow these steps.
Shut down your Mac. Turn your Mac on and immediately press and hold the command+option+P+R keys. Continue to hold the command+option+P+R keys for a minimum of 20 seconds. After 20 seconds, you can release the keys. Your Mac will continue the startup process.
After the resetting of PRAM or NVRAM, you can use the system preferences to set the time, change the system settings and other things that have been changed to default.
How to Reset SMC
Mac also has a hardware component System Management Controller (SMC) that stores crucial settings. It deals with power management, temperature monitoring and fan control, status lights, keyboard backlights, and few other things.
If there is an issue with SMC, your Mac system may start showing lots of problems including excessive fan noise, slow performance, battery issue and more. If you reset the SMC, your Mac system goes to default stage and it solves many problems.
Apple wants you to touch SMC only if all other configuration things didn’t work.
Steps to reset SMC depends on the type of system you own. It is different for Mac with the removable battery, Mac with built-in battery and desktop system.
Steps for MacBook with removable battery
Shutdown the computer, remove the MagSafe plug from the machine and remove the battery. Then press the power button for 5 seconds and release. Now put the battery back in and reconnect the MagSafe cord. Turn on the system.
Steps for MacBook with non-removable battery
Turn off the machine and keep the power adapter plugged in. Press the shift-option-control (on the left side of the machine) and the power button at the same time for free seconds. Then turn on your system
Steps for desktop systems
Shut the machine down and unplug it from the power. Now, Press and hold the power button for 5 seconds. Then plug it back in and turn it on.