My monitor says no signal
"No signal" means the monitor is working but is not getting a picture from the computer. The fault is often a loose cable or the wrong input.
Check the computer first
- Make sure the computer itself is on. Look for lights or listen for the fan.
- Move the mouse or press a key, as it may be asleep.
- If it is a laptop, try pressing the Windows key and P to switch the display mode, as it may be sending the picture elsewhere.
Check the cable
- Turn the monitor off.
- Unplug the video cable at both ends and plug it back in firmly.
- If it has screws, tighten them gently by hand.
- Switch the monitor back on.
If you have a spare cable, try it. Cables do fail.
Check the monitor input
Monitors often have several inputs, such as HDMI 1, HDMI 2 and DisplayPort. Use the monitor's buttons to open its menu and choose Input or Source. Pick the one your cable is plugged into. Some monitors have an auto option, which can sometimes pick wrongly.
Use the right socket on desktop computers
On a desktop computer, there may be video sockets on the graphics card and also on the motherboard. If your computer has a separate graphics card, the cable normally goes into the card, not the one above it. If you are not sure, check the manual rather than moving things around inside.
Try a restart
Turn the computer off, wait 30 seconds, unplug the monitor power lead for a minute and then start again, with the monitor switched on first.
Test another way
If you can, try the monitor with another computer, or your computer on a TV. This shows whether the fault is with the screen or the computer.
When to get more help
If you still have no signal with a good cable and the right input, either the monitor or the computer's graphics may have a fault. Please do not open the computer. Tell us what you see, including any beeps or lights, and the makes of the monitor and computer.