Symptoms
- Monitor shows 'No Signal' over DisplayPort specifically
- Screen goes black after the computer wakes from sleep
- Switching to HDMI on the same monitor works fine
- Cable feels loose or doesn't click into place
Likely causes
- CommonDisplayPort cable not fully clicked inDisplayPort connectors have a locking clip that must seat fully to maintain a stable connection.
- CommonCable doesn't support the resolution/refresh rate in useOlder or cheap DisplayPort cables may not handle high resolutions or high refresh rates reliably.
- PossibleMonitor or GPU DisplayPort version mismatchMixing very old and very new DisplayPort standards can cause handshake failures.
- CommonSleep/wake handshake failureSome GPU and monitor combinations fail to re-establish a DisplayPort signal after the PC sleeps.
What to do
- Firmly push the DisplayPort cable in until you feel or hear the locking clip engage at both ends.
- Try a different DisplayPort cable, especially if the current one is unbranded or very long.
- If the monitor has both DisplayPort and HDMI, test HDMI to see if the problem is DisplayPort-specific.
- Update the graphics driver, since DisplayPort sleep/wake issues are frequently fixed in newer driver releases.
- In the graphics driver's control panel (NVIDIA or AMD), disable any DisplayPort power-saving or 'deep sleep' features if present.
- Lower the resolution or refresh rate temporarily to see if a high setting is beyond the cable's supported bandwidth.
- Reboot with the cable connected rather than waking from sleep, to see if the issue is specific to wake-up handshakes.
Tools and parts
- None
DisplayPort cableSearch: “DisplayPort 1.4 cable”
When to call a pro
If the problem only happens on wake from sleep and persists after a driver update, it's often a known compatibility quirk between that GPU and monitor model; check the manufacturer's support site or consider using HDMI instead.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.