HDMI connection issues, solutions and workarounds

If your TV only has one HDMI input, consider upgrading your home theater receiver to one with HDMI switching for multiple components.

While different HDMI versions may cause some of the interoperability issues experienced by consumers, most of the problems are caused by a manufacturer's improper or incomplete implementation of the technology. Some incompatibilities in the digital "handshake" of the HDCP copy-protection code still exist between HDMI-connected components, especially when routed through an HDMI-equipped home theater receiver. Whenever problems like these are discovered, the HDMI standards group contacts the manufacturer and requires that the issue be resolved. In some cases, products have been recalled.

Beyond the initial handshake, there are other possibilities for miscommunication between components. At the beginning of the article, I mentioned that HDMI supports two-way communication between a video source and a TV. Part of that digital conversation is known as "EDID" (Extended Display Identification Data), which describes the TV's capabilities to the source component. EDID info typically includes the manufacturer name, product type, screen resolution, and color depth. Thanks to EDID, two devices can not only talk to each other, they'll actually know whom they're talking to. And that makes auto-configuration possible, which simplifies your setup process.

Keeping all that in mind, here are some of the most common HDMI connectivity issues we've heard about from customers, along with possible solutions or workarounds:

No picture or sound using HDMI from DVD player to TV
Some video components come from the factory with the HDMI output set to "off." You can switch it to "on" via the player's setup menu, or sometimes by pressing the "HDMI" button on the component's front panel or remote.

No sound when using the HDTV's HDMI input
Most TVs lack built-in decoding for Dolby Digital and DTS surround sound, and can only play 2-channel audio. But many HDMI-equipped video components come from the factory set up to send multichannel audio. Usually, just changing the component's audio setting to "2-channel (PCM)" solves the problem.

No picture when connecting a cable box to an HDTV
This is usually the fault of the cable box, as many local cable providers have still not upgraded their customers' equipment with new firmware or new boxes to make them fully compliant and compatible with HDMI-equipped TVs and A/V receivers. Customers should report problems to their local cable providers. As with most HDMI-related connectivity issues, one effective workaround is to use component video connections and optical or coaxial digital audio connections.

No closed captions displayed when using HDMI connections
Unfortunately, the HDMI spec doesn't include any requirement for carrying closed captioning data. So, if you connect a video component like an HD cable or satellite receiver or DVD/Blu-ray player to your HDTV using HDMI, you won't see conventional closed captions. If you need to view closed captions from your cable or satellite box, use a component video connection — the closed captions will pass through and you'll still enjoy a high-def picture.

A related issue is that many DVDs and Blu-ray discs simply aren't encoded with closed captioning data. However, most discs are encoded with subtitles, which are similar to closed captions, and subtitles are compatible with HDMI. In fact, a growing number of content providers are using a particular type of subtitling called "Subtitling for Deaf and Hard of Hearing," which is optimized for people with hearing disabilities. While not all discs include subtitles, virtually all DVD and Blu-ray players are capable of decoding subtitles if they're present.

Can't get multichannel audio with an A/V receiver connected between the video source and an HDTV
We've mentioned HDMI's intelligent two-way communication between components, but sometimes it actually contributes to hookup problems. Normally, the display tells the source device about its video and audio capabilities. Virtually all TVs are limited to 2-channel audio playback. Since many A/V receivers employ a "repeater" type of HDMI switch, the receiver simply passes the 2-channel information to the source, despite the receiver's multichannel capabilities. So, the player sends only 2-channel audio to the receiver, rather than high-quality surround sound.

Solving this type of HDMI interoperability issue requires sophisticated technology, like this video switcher/processor from Key Digital. Now, one handy workaround would be to simply run a separate optical or coaxial cable for audio. Unfortunately, many HDMI-equipped components are designed to turn off digital audio outputs when the HDMI output is in use. We have found that some models do this and some don't (even from the same brand), and going forward, we expect to see more models switching off their digital audio outputs.

Another receiver-related HDMI sound issue is that some receivers aren't designed to pass audio through their HDMI connections — they perform video switching only. To get multichannel audio from these receivers, you need to connect an optical or coaxial digital cable from your video source to the receiver. Only a few entry-level receivers still have this limitation, but it's something to be aware of.

Plug into the future

HDMI isn't just nice to have, it's now essential to maximize your home theater's performance. You may have noticed that upconverting DVD players limit the resolution on the component video output to 480p — if you want 720p or 1080i/p, it's only available via HDMI.

When high-definition discs launched, it initially appeared that HD-quality signals would only be available from a player's HDMI output (the signal available from the component video outputs would be "down-rezzed" to slightly-better-than-DVD quality to discourage piracy). Millions of owners of non-HDMI-equipped TVs got a reprieve when the studios decided not to activate this "feature" at that time. But some in the movie industry predict that this down-rez flag could begin appearing on high-definition discs beginning in 2010 or 2012. And there is no legal way to convert the digital signal from a high-definition source to an analog component video signal to send to a non-HDMI HDTV.

The bottom line is that if your equipment doesn't include HDMI connections, at some point you will miss out on the best-quality picture and sound available. If you've seen the amazing picture quality available from top-notch DVD players and high-def disc players, you know you could be missing a lot.