HDMI Trouble Shooting

Our HDMI troubleshooting guide below will help you diagnose any quality or loss of signal you are encountering when using a CMD module with HDMI capability

Length of Cable Run

Like all cables as you increase the length, you also increase the attenuation, resulting in a weaker/loss of signal.

For an HDMI installation, it is advised that the run does not exceed 5m. It is possible to have longer runs (up to 15m) but you would require a high-quality HDMI cable. Exceeding a 5m run on standard HDMI cables may result in the signal not being strong enough to display the picture clearly, or no picture will be displayed at all.

Please note that the cable run is from the source device to the screen, not just the cable length supplied with your CMD Module.

Joints/Switching Units

Too many joints in an HDMI run can often be the cause of poor signal quality.

We have also encountered problems caused by “data Multi-Format Video over HDMI Transmitter & Step-In Commander” when they have been setup incorrectly on dip switches.

Low grade/specification cable

Unfortunately, not all HDMI cables are the same and a low grade, low specification cable could cause problems with the transmission. CMD use a high-grade HDMI cable manufactured to the HDMI 1.4 specification.

Damage to HDMI Cable/Plugs

A tight bend radius on an HDMI cable can degrade the signal. If your HDMI socket is located in an access floor box, the cable may be getting bent too far when the lid is shut. A simple solution to this could be to use a right angled HDMI adapter as it is recommended that a minimum bend radius of 25mm is applied during installation.
Further to this, any damage to the HDMI plugs (such as being crushed) could result in poor signal quality.

If you have checked all the above points and you are still experiencing issues with your CMD module, the next step would be to bypass the CMD module. Plug the source (I.E PC or Laptop) directly into the HDMI socket in your access floor box/wall socket and see if the signal is better.

All CMD power modules are rigorously tested before they are released to our customers so if the signal improves when the module is disconnected, this would suggest there is a problem with the data installation. Possible causes may include; low specification HDMI cables, too many HDMI connections or overall/combined data cable installation exceeding the recommended cable length etc. If you experience any problems of this nature, please call our Technical Sales Team so we can help you find the right solution.

If you experience any problems of this nature, please call our Technical Sales Team (+44 (0) 1709 829511) or e-mail them so we can help you find the right solution.