Verified for macOS Tahoe 26.2

Fix Guide: Mac Sleep Wake Failure on macOS Tahoe 26.2

Symptom: Your Mac won't wake up from sleep (black screen), or it restarts unexpectedly after you close the lid, showing a "Your Mac restarted because of a problem" message.

This is frequently caused by a conflict with "Power Nap" or an external device preventing the CPU from entering a low-power state.

Recommended Troubleshooting Tool

Before proceeding with manual fixes, we recommend using CleanMyMac X. Quickly identify high CPU apps and optimize system memory with one click.

- [Download CleanMyMac X Free Here](#)

- [Browse 240+ Premium Mac Utilities on Setapp](#)


Fix 1: Reset the SMC (System Management Controller)

*Note: For Apple Silicon (M1/M2/M3) Macs, just shut down for 30 seconds.*

For Intel Macs with the T2 chip:

  1. Shut down your Mac.
  2. Hold the Power Button for 10 seconds, then release.
  3. Wait a few seconds and turn the Mac back on.

Fix 2: Disable Power Nap & Proximity Wake

Power Nap can cause the Mac to wake up to check mail but fail to return to sleep properly.

  1. Go to System Settings > Battery > Options.
  2. Set "Enable Power Nap" to Never.
  3. Set "Wake for network access" to Never.

Fix 3: Identify the "Wake Reason" via Logs

If the Mac is waking up on its own, use this command to see what triggered it:

  1. Open Terminal.
  2. Run:
pmset -g log | grep -i "Wake Request"
  1. Look for the "Owner" (e.g., com.apple.alarm). This will tell you which app or process is the culprit.

If you use an external monitor, try waking the Mac with the lid open before connecting the HDMI/DisplayPort cable.