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_armedIf 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.
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.