Monitor Not Detected Over HDMI? How to Fix It
A monitor that shows “No Signal” or is not detected by your computer is usually a simple fault. Work through these steps in order, from the quickest checks to the more involved ones.
1. Check power and the input source
Make sure the monitor is on and its power light is lit. Then use the monitor’s on-screen menu or input button to select the right input (HDMI 1, HDMI 2 or DisplayPort). Many monitors do not switch inputs automatically.
2. Reseat or swap the cable
Unplug both ends of the cable and plug them back in firmly. If you have another cable, try it: cables fail more often than monitors. For high resolutions and refresh rates, use a cable rated for the mode you want, such as HDMI 2.1 or a certified DisplayPort cable.
3. Try another port
Connect to a different port on the monitor and on the computer. On desktop PCs, plug the cable into the graphics card, not the motherboard’s video output, unless you are using integrated graphics.
4. Restart with the monitor connected
Turn the computer off, connect the monitor, then turn everything on. Some systems only detect a display at startup.
5. Check display settings
On Windows, press Windows + P and choose an option that includes the second screen, then open Settings, System, Display and select Detect. If the resolution or refresh rate is set higher than the monitor supports, the screen can go blank; start the system in safe mode or connect a different display to lower it.
6. Update the graphics driver
Install the latest driver from your graphics card or laptop maker. For laptops, also check the manufacturer’s site for chipset and display updates.
7. Adapters and docks
If you connect through a USB-C dock or adapter, make sure the USB-C port supports video output (DisplayPort Alt Mode or Thunderbolt). See our docking stations and the wider accessories range. If another monitor works on the same cable and port, the fault is in the first monitor.
Still no picture? Test the monitor with a different computer to work out whether the monitor or the source is at fault. Browse our monitors if it is time to replace it.