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HDMI: no signal and HDMI-CEC explained

HDMI is the cable that carries picture and sound between your TV and devices such as a Sky box, games console or soundbar. If the TV says "no signal", or if devices turn on by themselves, this guide may help. Menu names differ by brand.

Fix "no signal"

  1. Check the device (Sky box, console, Blu-ray player) is switched on.
  2. On the TV remote, press Source or Input.
  3. Choose the HDMI number the device is plugged into.
  4. Check the cable is pushed in firmly at both ends.
  5. Try a different HDMI socket on the TV.
  6. Try a different HDMI cable if you have one.

Do a quick power reset

  1. Turn off the TV and device at the wall.
  2. Unplug the HDMI cable from both.
  3. Wait a minute.
  4. Plug everything back in and switch on, TV first.

What is HDMI-CEC?

HDMI-CEC lets devices control each other through the cable. For example, switching on your console can switch the TV on, or the TV remote can adjust the soundbar volume. It is helpful, but sometimes causes odd behaviour.

Brands use different names for it, such as Anynet+ on Samsung, Simplink on LG, Bravia Sync on Sony and Viera Link on Panasonic. Look in the TV settings under General, System or External devices.

If CEC causes problems

  • Devices turning on or off by themselves can be fixed by turning CEC off on the TV.
  • If your soundbar or remote stops working, try turning CEC on.
  • Turn it off or on in the TV's menu, then switch everything off and on again.

Special HDMI sockets

Some TVs have a socket marked ARC or eARC. This is the one to use for a soundbar. See our soundbar guide.

When to get more help

Get in touch if the picture flickers, goes black every few minutes, or shows sparkles. This often means the cable is faulty or not suitable for 4K. We can recommend the right cable.

Did this help? If you are still stuck, email Vision Tech and tell us what you can see on the screen. Menus and button names can differ slightly between versions and makes. If something does not match, stop and ask rather than guess.

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