Why won’t my iMac wake up?

Answered by Stephen Mosley

There can be several reasons why your iMac won’t wake up from sleep. Let’s go through some troubleshooting steps to help you resolve this issue.

1. Hard shut down and restart your Mac: Press and hold the power button on your iMac until it shuts down completely. Wait for a few seconds and then press the power button again to turn it on. This can sometimes resolve temporary software glitches that may be causing the sleep/wake failure.

2. Reset the System Management Controller (SMC): The SMC manages various hardware functions on your Mac, including sleep and wake operations. Resetting it can often fix sleep-related issues. The steps to reset the SMC vary depending on the model of your iMac. You can find the specific instructions on Apple’s support website.

3. Reset the Non-Volatile Random Access Memory (NVRAM): NVRAM stores certain settings on your Mac, including display resolution and volume settings. Resetting it can sometimes resolve sleep/wake problems. To reset NVRAM, shut down your iMac and then turn it on while holding down the Command + Option + P + R keys. Keep holding them until you hear the startup chime for the second time, and then release the keys.

4. Boot your Mac in Safe Mode: Starting up your Mac in Safe Mode can help identify and resolve any software conflicts or issues that may be preventing it from waking up properly. To do this, shut down your iMac and then turn it on while holding down the Shift key. Release the key when you see the Apple logo. If your iMac wakes up successfully in Safe Mode, restart it normally and see if the issue persists.

5. Run First Aid in macOS Recovery: If none of the above steps resolve the sleep/wake problem, it’s worth checking the health of your Mac’s startup disk. Restart your iMac and immediately hold down the Command + R keys until you see the Apple logo. This will boot your Mac into macOS Recovery. From there, select “Disk Utility” and choose your startup disk. Click on the “First Aid” button to run a disk check and repair any errors if found.

It’s important to note that if the sleep/wake issue persists after trying these troubleshooting steps, it may indicate a hardware problem. In such cases, it’s recommended to contact Apple Support or visit an authorized service provider for further assistance.

I hope these steps help you resolve the sleep/wake failure on your iMac.