What Am I Using?
External monitor says no signal?
Check the monitor input, cable, dock and display settings. Follow the steps that match whether your computer can detect the monitor.
Does the computer list the external display?
Switch the monitor to the input that matches the cable, such as HDMI 1. Then open your device’s display settings.
Device and operating system
Send a picture to the detected display
The device can identify the screen. Its projection mode or video setting may still need attention.
- Choose Extend or Mirror in display settings and give the monitor a moment to respond.
- If a recent resolution or refresh-rate change caused the blank screen, restore the last working setting using the primary display.
Check the physical video path
A missing display can be caused by its input, a cable, a dock or a port without video support.
- Check the monitor input and reconnect both cable ends. If possible, connect directly without the dock.
- Try a known working cable or a different video-capable port. Some USB-C ports carry charging and data only.
Use a working screen or a known source
A second source can show whether the monitor can receive a picture on that input.
- Try the built-in display if available, or test the monitor with another working source and the same input.
- Tell support which cable, port and monitor input you used, and whether the monitor menu is visible.