HDMI Input Not Working on Your CommBox?
If one of your HDMI inputs isn’t working, follow these simple steps to fix it and get your screen displaying properly.
Applies To
All CommBox Touchscreens and Commercial Displays
Step-by-Step Instructions
Step 1
Check the correct input is selected
Make sure your CommBox screen is set to the HDMI port you're using. Use the input/source button to switch between HDMI ports. This can be found in the side menu or swipe up for the device settings on Interactive Displays.
Step 2
Avoid using adapters or docks
If you're using an adapter or docking station, try connecting directly with a standard HDMI cable.
💡 Tip: Over 85% of display issues are caused by faulty adapters or docks that can't handle 4K resolution.
Step 3
Swap cables and devices
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Try a different HDMI cable.
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Try connecting a different laptop or device—one that you know works.
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This helps rule out cable or device faults.
Step 4
Adjust display resolution
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On Windows: Right-click the desktop and select Display settings.
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Scroll down to Display resolution and test different options until the screen fills correctly and touch is responsive.
💡 Tip: Lowering or raising the resolution can help if your device isn’t automatically scaling to the CommBox screen.
Step 5
Set the display mode to Extend
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Press the Windows + P keys together.
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Choose Extend instead of Duplicate.
This ensures the screen isn’t mirroring, which can cause display issues on some devices.
Step 6
Try a different HDMI port
Switch to another HDMI input on the CommBox screen to see if the issue is with the port on your computer.
Troubleshooting / What to Do If It Doesn’t Work
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Still no signal? Try restarting both the CommBox screen and your laptop.
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Touch not responding? Check if the correct USB touch cable is plugged in as well.
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Image still cut off or blurry? Try a different resolution or refresh rate.
If you’ve tried all of these steps and it’s still not working, log a ticket on the Support Portal.