HDMI Basic Troubleshooting Guide

Writing this to pass on some basic knowledge regarding connecting on HDMI to TV/AV equipment to minimise any problems people may have with display issues.

Warning Never connect and disconnect HDMI cables and equipment while your devices are powered on (hot plugging cables). The HDMI cables carries a low DC voltage when connected.

Why problems Occur

When HDMI Players, gaming consoles and displays are powered on 24-hours a day without switching to standby mode or switching to another HDMI source, HDMI issues occur because of unstable voltage on HDMI ports on Source / LCD or AC/DC adaptor and the majority of issues can be solved by power cycling your equipment.
Checking the equipment manufacturers website for firmware upgrades is also strongly advised.

Not all HDMI cables are created equal

As of the HDMI 1.4 specification, the following cable types are:-

Standard HDMI Cable – up to 1080i and 720p
Standard HDMI Cable with Ethernet
Standard Automotive HDMI Cable
High Speed HDMI Cable – 1080p, 4K 30 Hz, 3D and deep colour
High Speed HDMI Cable with Ethernet

Simply this means “check your cables” there is no point trying to get 4K on a device that’s connected with a “Standard” HDMI cable as the equipment during the HDMI handshake will just step down the display to the best achievable resolution. If you need a replacement one I would recommend the Amazon Basics one as its cheap and gets good test and review results. Gold Connectors are not worth the extra money as to get any benefit both male and female sides have to be gold.

Signs and Symptoms of a bad HDMI Cable

Cables and connections can wear out or endure damage from heavy use, coiling, and bending or when you roughly connect and disconnect them multiple times. When your video and audio quality begin to suffer, the cable might be the cause, symptoms can include:-

  • “Shooting stars” or sparkling in the picture
  • Fuzzy or blurry picture
  • No picture or intermittent picture
  • No sound or intermittent sound
  • Weird colours in the picture
  • Remotes don’t work

Checks:

  1. Check any cables and sockets for bent or broken pins.
  2. Check that the cable connects firmly into the socket, as occasionally the cover on the end of the HDMI cable can be a little to large to ensure a good connection.
  3. Check that the weight of the cable is not pulling the connector out of the socket slightly. This can be solved by either using a cable tie base and cable tie to support the cable or by using a shorter cable.
  4. Check your cables by running them through your fingers and feeling for any cuts or nicks. This goes especially if you have pets in the house as my Felis catus subtype:gormless has attacked the cables more than once.

Other culprits could be RFI interference from nearby cordless phones / base stations or cheap and not cheerful smart bulbs or cheap and nasty unshielded power supplies. MyVolts are good for replacements.

Guide V1.0 Completed 5/3/2021 - Suggestions and Additions welcome

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