TV says No Signal: How to fix it
"No Signal" means the TV is not receiving a picture on the input you are watching. It is nearly always the wrong input, a loose cable, or the source device, not a broken TV. Work through these in order and most people are sorted within a couple of minutes.
First: Check you are on the right input
This is the most common cause by a wide margin. Press the Source or Input button on the remote and step through the inputs, HDMI 1, HDMI 2, HDMI 3, until you land on the one your box, console or stick is plugged into. A power cut or an accidental button press often leaves the TV on an empty input. While you are there, rename each input so you know which is which next time.
Check the source device is actually on
The TV shows No Signal whenever the thing feeding it is off or asleep. Make sure your set-top box, console, Blu-ray player or streaming stick is powered on and awake, and look for its own standby light. A streaming stick in an HDMI port often needs its separate USB or mains power connected as well; plugged into the HDMI alone, some simply do not start.
Reseat the HDMI cable, both ends
A cable that has worked loose, or is quietly failing, is the next suspect. Unplug the HDMI cable and push it firmly back in at both ends, the TV and the device. Try a different HDMI port on the TV. If you have a spare cable, swap it in, because HDMI cables fail far more often than TVs do, and a dead cable looks exactly like a dead input.
Power-cycle everything
Turn off the TV and the source device, then unplug both at the wall for 30 seconds. Power the source up first, then the TV. This forces the two to shake hands again over HDMI-CEC, the handshake that occasionally fails and leaves the screen blank even though everything is connected correctly.
For an aerial or cable feed
If the No Signal is on live TV through an aerial or a cable connection rather than HDMI, the tuner is not getting a broadcast. Check the aerial or coax lead is pushed firmly into the socket on the wall and the back of the TV, run a channel retune from the settings menu, and check whether there is a known transmitter fault or outage in your area before assuming the TV is at fault.
If nothing works, find out what is faulty
Move the parts around to corner the fault. Plug the source device into a different TV: If it works there, the first TV's input or the cable is the problem. Or plug a different device into this TV: If that works, the original source device is the culprit. Whichever way the fault follows tells you exactly what to replace or have serviced.
Questions people ask
Why does my TV say No Signal when everything is on?
Almost always the wrong input or a loose HDMI cable. Cycle through the inputs with the Source button until you reach the one your device uses, then reseat both ends of the HDMI cable and try a different HDMI port on the TV.
How do I fix No Signal on HDMI?
Check you are on the matching HDMI input, make sure the source device is powered on and awake, reseat or swap the HDMI cable, and power-cycle the TV and source together, powering the source up first and the TV second.
Is No Signal a sign my TV is broken?
Rarely. It means the TV is not receiving a picture on that input, which is usually the source device, the cable, or simply the wrong input. Test the source on another TV, or another device on this TV, to confirm the set itself is fine.
If the picture returns but the sound does not, see no sound on your TV. For the cable itself, the HDMI cable guide and HDMI ARC vs eARC explain which lead does what.