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rosswd/reset.md

Created June 4, 2019 22:29
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SMC and PRAM reset on non T2-Security chip Intel Macbooks
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reset.md

TLDR

  • Power issues, do an SMC reset. Display resolution, sound or startup disk issues, do a PRAM reset.

SMC Reset

  • Apple Menu > Shut Down
  • Shift + Ctrl + Opt (left side) & Power button at the same time. Hold for 10 seconds.
  • Release all keys
  • Power on your Mac

PRAM Reset

  • Apple Menu > Shut Down
  • Power on and immediately hold down the following keys: Opt + CMD + P + R. Hold for 20 seconds.
  • If your Mac emits a startup sound, you can release the keys after the second startup sound
  • Power on your Mac
  • Once your Mac finishes starting up, check your sound volume, display resolution and startup disk in System Preferences

SMC (System Management Controller)

  • Responds to key presses, lid opening/closing
  • Battery management, Thermal management
  • SMS (Sudden Motion Sensor)
  • Ambient Light Sensor, Keyboard backlight
  • SIL (Status Indicator Light) management
  • Battery Status Indicator Lights

Reset Reasons

  • Battery charging issues
  • High fan speed without high usage
  • Magsafe charging light issues
  • The CPU is underperforming even though not under load
  • Keyboard and status light issues
  • Power button and lid power issues

NVRAM and PRAM

  • Non-Volatile RAM and Parameter RAM
  • Stores settings for sound, resolution, startup disk selection, time zone and recent kernel panic information
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