I just updated my desktop computer and now it won’t turn.
I just updated my desktop iMac and now it won’t turn on or boot up
iMac 27″, macOS 10.12
If your Mac doesn't seem to turn on after you press the power button, follow these steps:
- Make sure that your Mac is connected to AC power. If it doesn't have a built-in display, make sure that your external display is connected to power, connected to your Mac, and turned on.
- Press and hold the power button on your Mac for at least 10 seconds, then release.
- Every Mac has a power button. On notebook computers that have Touch ID, press and hold Touch ID.
- If you see no change on your Mac, press and release the power button normally.
- If your Mac now turns on but stops at some other screen during startup, follow the steps for when your Mac doesn't start up all the way.
If your Mac still doesn't turn on, please contact Apple Support.