Computer Cause Interference on TV

Have you ever experience that your Computer Cause Interference on TV screen? This is something that happened to me personally and it took me a while to resolve. First let’s start with my setup.

I had a Media Player connected to my TV to watch movies and listen to music. I decided to replace the media player with a full computer because the media player’s firmware could not keep up with all the new video file formats. So I built myself a new computer with a dedicated Graphics Card with a HDMI out so that I could connect it directly to my TV. Everything worked fine, but as soon as I switch back to my Satellite TV channels, all channels shows interference from the computer. This only occur while the computer was switch on. As soon as I shut down the computer the interference disappeared. I started to search the internet and found lots of “solutions” but most of them made no difference.

Computer Cause Interference on TV

Computer Cause Interference on TV: Things I tried


  1.  I moved the computer and the TV’s power plug so that they are not on the same multiplug so that they are in different wall plugs. (This made no difference)
  2. I wrapped the Coax Cable (from the Satellite TV Decoder) and HDMI cable (from the Computer) with tinfoil to make sure there is no signals between the two cables. (This made no difference)
  3. I moved the computer about 1.5 meter away from the TV to ensure that it’s not maybe the computer power supply that is causing the interference. (This made no difference)
  4. I moved all power cables away from the Coax Cable from the Satellite TV Decoder to prevent any power interference. (This made no difference)

Then I realised that if I leave the computer on and unplug the HDMI cable from the TV the interference is gone. This meant that the issue is not the computer nor the power cables. It’s something to do with the HDMI cable or the display itself.

I also realised that my TV makes a very soft humming sound when the HDMI cable is plugged in. Then I started to play around with the display settings on the computer. First thing I did was changing the Screen Refresh Rate on the graphics card’s display driver. That also made no difference.

Eventually I found the problem! I had the Display Resolution on 1920×1080. This was the default setting and also recommended setting as per the size of the TV monitor. I decrease the Display Resolution to 1360×768 and that solved the problem. I would suggest, if your computer cause interference on TV, start by decreasing the Display Resolution. I might save you a lot of time while troubleshooting the issue.

Hi, my name is Jeanne De Villiers. I am an IT Professional with 15 years experience and also co-owner of an IT company. We provide network and IT infra- structure design services. As a part time hobby I'm doing some Internet Marketing and website design.

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