macbook promacosnvrampower-management
I've bought a used MacBook Air (Mid 2013) running Yosemite and I'd like to restore every setting to defaults, as in, start over with a fresh clean OS.
What are the things I have to run to make sure the system is good conditions before performing a reinstall?
Should I reset NVRAM and SMC to set stuff like volume and mouse speed to default, or a OS reinstall via recovery will take care of that?
Thanks!
It doesn't work
My Pentalobe and Torx bits arrived today and I tried swapping the drives. When I put the 256 GB drive in my Macbook Pro, it doesn't boot and displays this image
I tried holding down opt to boot to a usb drive and do a fresh install of Mavericks on the drive.
When I attempt to boot from the USB drive, the crossed out circle image is displayed again.
I've also tried holding down shift during boot to boot into safe mode. The neutral gray screen displays for a longer time, but eventually the crossed out circle appears again.
A fresh OS install won't reset the hardware, SMC or PRAM. It might be well worth checking both those are correctly reset before going so far as a wipe & install.
Reset the PRAM first - hold Cmd/Opt/P/R at the chimes & wait for the chimes to happen a second time.
SMC varies per machine, Mac Pro is sufficient to power off & leave the mains plug out for a minute. MacBooks are different - http://support.apple.com/kb/ht3964 covers all the variations.
Extract :
Resetting the System Management Controller (SMC)
Resetting the SMC on Mac portables with a battery you can remove
- Shut down the computer.
- Disconnect the MagSafe power adapter from the computer, if it's connected.
- Remove the battery.
- Press and hold the power button for 5 seconds.
- Release the power button.
- Reconnect the battery and MagSafe power adapter.
- Press the power button to turn on the computer.
Resetting the SMC on portables with a battery you should not remove on your own Note: Portable computers that have a battery you should not remove on your own include MacBook Pro (Early 2009) and later, all models of MacBook Air, and MacBook (Late 2009).
- Shut down the computer.
- Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
- On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
- Release all the keys and the power button at the same time.
- Press the power button to turn on the computer.
Note: The LED on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.
Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve
- Shut down the computer.
- Unplug the computer's power cord.
- Wait fifteen seconds.
- Attach the computer's power cord.
- Wait five seconds, then press the power button to turn on the computer.
Best Answer
Erasing a hard drive with Recovery HD (or better - a flash drive) will remove everything. You don't need to do a NVRAM/SMC reset (you can if you'd like)