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Fix a monitor that will not sleep

We'll fix Windows or macOS power settings, monitor settings, and wake sources that prevent sleep.

Troubleshooting · Home maintenance
5–15 min
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Steps

Goal: Fix power settings and wake sources so the monitor and PC sleep correctly.

Check Windows power settings

Goal: Set screen and sleep times in Windows.

  • Open Settings, System, Power & sleep. Set Screen to turn off after 5–15 minutes. Set Sleep to 15–30 minutes.
  • Open Power Options, Change advanced power settings. Under Sleep, set “Allow wake timers” to Disable.
  • Good: Settings applied. If the PC still will not sleep, check wake sources.
  • Bad: Run powercfg /lastwake to see what is waking the PC.

Check macOS energy settings

Goal: Set display sleep in macOS.

  • Open System Preferences, Energy Saver. Set “Turn display off after” to 10–15 minutes.
  • Good: Display sleeps. If the Mac wakes immediately, check for wake sources.
  • Bad: Close apps that may prevent sleep (e.g. video, streaming).

Disable wake sources

Goal: Stop USB devices and wake timers from waking the PC.

  • In Windows: run powercfg /lastwake to see the wake source. In Device Manager, open the device, Power Management, uncheck “Allow this device to wake the computer”.
  • Good: PC stays asleep. If the monitor stays on when the PC is off, check the monitor menu.
  • Bad: Enable power-saving in the monitor menu; some monitors have “Auto power off”.

When to get help

Rarely needed. If the monitor never sleeps when the PC is off, try unplugging the video cable. The monitor may be detecting a phantom signal.

Verification

  • The display turns off after the set time when idle.
  • The PC goes to sleep and stays asleep (does not wake immediately).
  • No unnecessary wake sources enabled.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Power settings Set Turn off display and Sleep in Windows or macOS.
  2. Wake timers Disable Allow wake timers in Windows.
  3. Wake sources Use powercfg /lastwake and disable USB wake.
  4. Monitor settings Enable power-saving in monitor menu.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • OS and power plan
  • Wake source (powercfg /lastwake)
  • Monitor model and power-saving setting
  • Steps already tried

Are power settings set to turn off the display and put the PC to sleep?

Power settings must not be "Never" for screen and sleep.

Check Windows: Settings, Power & sleep. Or macOS: Energy Saver. Set correctly: screen off 5–15 min, sleep 15–30 min. Set to Never: change to a time value.

Yes No

You can change your answer later.

Set power settings

Set "Turn off display" and "Put computer to sleep" to 5–30 minutes. Disable "Never".

Done

Are wake timers disabled?

Wake timers can prevent or interrupt sleep.

Power Options, Change advanced power settings. Sleep > Allow wake timers: Disable. Good: disabled. Bad: enable and check wake sources.

Yes No

You can change your answer later.

Disable wake timers

Set Allow wake timers to Disable. Test sleep again.

Done

Does the PC wake immediately after sleep?

USB devices or network can wake the PC.

Run powercfg /lastwake to see wake source. In Device Manager, disable "Allow this device to wake the computer" for USB devices you do not need. Good: sleep works. Bad: monitor may have power-saving off—check monitor menu.

Yes No

You can change your answer later.

Check monitor power-saving

Use monitor menu. Enable Power Saving or Auto power off. Unplug video cable when PC is off if monitor still stays on.

Done

Done

Sleep and display off working.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would a monitor not sleep?
Power settings set to "Never", wake timers, USB or network activity waking the PC, or monitor power-saving disabled. Check Windows/macOS power settings first.
Can I fix a monitor that will not sleep myself?
Yes. Set "Turn off display" and "Put computer to sleep" in power settings. Disable wake timers. Check the monitor menu for power-saving. Unplug USB devices that may wake the PC.
What wakes the PC from sleep?
Wake timers, USB devices (mouse, keyboard, network adapter), network activity, or scheduled tasks. Use powercfg /lastwake in Windows to see what last woke the PC.

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