Purpose of Knowledge Article

A guide on how to fix the touch bar on a Mac laptop flashing issue

Resolution

The instruction varies based on the hardware your computer has

1. Determine if your Mac laptop is an Intel chip or an Apple silicon chip: (see https://support.apple.com/en-us/HT211814 for more information)
   1. MacBook Pro:
      MacBook Pro (13-inch, M1, 2020) and 2021 or later
   2. MacBook Air:
      MacBook Air (M1, 2020) and 2022 or later

2.  Determine if your Mac laptop has an Apple T2 Security chip: (see https://support.apple.com/en-us/HT208862 for more information)

   MacBook Pro	MacBook Air
   MacBook Pro (13-inch, 2020, Two Thunderbolt 3 ports) MacBook Pro (13-inch, 2020, Four Thunderbolt 3 ports) MacBook Pro (16-inch, 2019) MacBook Pro (13-inch, 2019, Two Thunderbolt 3 ports) MacBook Pro (15-inch, 2019) MacBook Pro (13-inch, 2019, Four Thunderbolt 3 ports) MacBook Pro (15-inch, 2018) MacBook Pro (13-inch, 2018, Four Thunderbolt 3 ports)	MacBook Air (Retina, 13-inch, 2020) MacBook Air (Retina, 13-inch, 2019) MacBook Air (Retina, 13-inch, 2018)

3. Resetting NVRAM and/or SMC. Use the Mac laptop's built-in keyboard as an external keyboard will not work correctly

   Mac laptop with Intel Chip and Apple T2 Security Chip	Mac laptop with Intel Chip without Apple T2 Security Chip	Mac with Apple silicon chip (M1 and M2)
   Try the following steps: Reset NVARAM Save your work, exit all programs, and shut down the laptop Turn on the laptop, then immediately press these four keys together: Option, Command P and R Hold it down for 20 seconds and your laptop may restart a few times and you may hear the startup sound as well Let go after 20 seconds The laptop should be booting up If the issue continues, try resetting the SMC Shut down the laptop Press and hold the power button for 10 seconds then release it (If your laptop has a Touch ID button, that is your power button) Wait another 10 seconds, then power on the laptop If the issue continues, shut down the laptop again Hold down these four buttons: Control and Option on the left side of the keyboard, Shift on the right side of the keyboard, and the power button Hold the buttons down for 7 seconds then release it Wait another 10 seconds then power on your laptop See instructions on How to Reset SMC on your Mac, specifically the "If you have a Mac with the T2 chip" section	Try the following steps: Reset NVARAM Save your work, exit all programs, and shut down the laptop Turn on the laptop, then immediately press these four keys together: Option, Command P and R Hold it down for 20 seconds and your laptop may restart a few times and you may hear the startup sound as well Let go after 20 seconds The laptop should be booting up If the issue continues, try resetting the SMC Hold down these four buttons: Control, Option, and Shift on the left side of the keyboard, and the power button Hold the buttons down for 10 seconds then release it Wait another 10 seconds then power on your laptop See instructions on How to Reset SMC on your Mac, specifically the "If you don't have a Mac with Apple silicon or the T2 chip" section	Reset SMC Make sure your Mac laptop power source is connected Restart the computer or shut it down and turn it on again

Additional Resources

• Reset NVRAM on your Mac
• Reset the SMC of your Mac
• Mac computers with Apple silicon
• Mac models with the Apple T2 Security Chip