Black screen or PC won't wake from sleep

Question

The monitor stays black after sleep, or the PC seems on but nothing responds until I force a reboot. What can I try?

Answer

1. Turn off Fast Startup

Fast Startup saves kernel state to disk and can cause resume glitches with some GPU or USB chipsets.

Control Panel → Power Options → Choose what the power buttons do → Change settings that are currently unavailable → uncheck Turn on fast startup → Save changes. Reboot.

2. Firmware and drivers

Install the latest BIOS/UEFI from your motherboard vendor and the latest GPU driver (clean install if you recently changed drivers). Sleep/wake bugs are often fixed in firmware and display drivers.

3. What wakes the machine

Open Command Prompt as Administrator and run:

powercfg -devicequery wake_armed

If an unexpected device wakes the PC constantly, you can disable Allow this device to wake the computer for that device in Device Manager → device Properties → Power Management.

4. Narrow it down

• Test with one monitor and minimal USB devices.
• Try ** Hibernate** instead of Sleep (if available) to see if the problem is sleep-specific.
• If only one game or app triggers it, update that app and disable fullscreen optimizations (right-click the .exe → Properties → Compatibility) as a test.

5. Logs (optional)

Event Viewer → Windows Logs → System. Look for Kernel-Power or Display errors around the time of the black screen. That can point to driver vs hardware vs power timeouts.

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Repeated failures after tweaks may be power-plan or service related; compare with a restore point or temporarily reset power settings (powercfg -restoredefaultschemes in an elevated command prompt). This resets custom plans.