Symptoms
- Screen goes black for a second or more, then comes back
- Happens randomly, not tied to any specific action
- Sometimes the screen doesn't come back until you move the mouse or press a key
- Happens more often under heavy use like gaming or video playback
Likely causes
- CommonGraphics driver crashing and recovering (TDR event)Windows can detect a graphics driver crash, reset it, and briefly blank the screen while doing so.
- CommonPower-saving/sleep settings triggering unexpectedlyAggressive sleep or display-off timers can cause unexpected blackouts.
- CommonLoose video cableA cable barely making contact can drop the signal briefly under vibration or heat.
- PossibleOverheating graphics cardA GPU that overheats under load can drop its display output until it cools slightly.
- PossibleFailing power supply (desktops)An unstable PSU can cause brief power drops that blank the screen.
What to do
- Update the graphics driver to the latest stable version and restart the computer.
- Check Windows Event Viewer (search 'Event Viewer') under 'System' logs for repeated display driver crash or TDR errors around the time of the blackouts.
- Adjust Power Options so the screen and sleep timers are set to reasonable, non-conflicting values.
- Reseat the video cable firmly at both ends and try an alternate cable.
- Monitor GPU temperature using a free tool like HWMonitor during heavy use to check for overheating.
- For desktops, listen and feel for excess heat, dust buildup, or unusual noise from the power supply and graphics card.
- If blackouts happen mainly under load, clean dust from fans and vents, and ensure the case has adequate airflow.
Tools and parts
- Compressed air (for dust cleaning)
When to call a pro
If temperatures are normal, the cable is good, and the driver is updated, but blackouts continue, especially under load, have a technician check the power supply and graphics card.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.