Skip to content
English
Log a ticket Customer portal
Book Training Now
  • There are no suggestions because the search field is empty.

What to do if your HDMI input isn't showing a signal

If your CommBox screen isn't detecting a signal from an HDMI source, follow these steps to check connections, settings, and cable quality.

Applies To

All CommBox screens with HDMI input support

Step-by-Step Instructions

Step 1

Check the HDMI port and connected device

  • Test the HDMI port by connecting a different device (e.g. another laptop or media player).

  • Restart your CommBox screen and reconnect the HDMI cable.

Step 2

Inspect the HDMI cable

  • Make sure the HDMI cable is firmly plugged in at both ends.

  • Try the same cable on another screen or try a different HDMI cable to rule out a faulty one.

Step 3

Select the correct HDMI input

  • On the CommBox screen, open the Inputs menu using the remote or touch controls.

  • Select the correct HDMI source that matches your plugged-in device.

Step 4

Adjust resolution settings

  • Some older devices or laptops may not support 4K.

  • Go to Inputs > Menu Settings and change the HDMI output resolution to 1920 × 1080.
    This can help when your device struggles to display in 4K.

💡 Tip: Not all devices auto-switch resolution. Manually setting it can make the screen detect the signal faster.

Step 5

Raise a support ticket if you've tried all the steps and the screen still shows ‘No Signal’: