Explaining HDMI while Solving the Cause of Blue-Screen Nightmares

May 2009

The nightmares

I relate this journey in hopes it will help you avoid your own.

Longtime readers know that I am a fan of HDMI. Any time a single cable can replace as many as 19 cables and all their functions, I’m a happy videophile. Add the fact that HDMI licensees must certify that their products are compliant with HDMI specifications before they can use the HDMI logo, I’m even happier. And the HDMI trade group certifies not just wires but the entire signal chain: receivers, processors, switchers, splitters, and amplifiers (all of which they collectively refer to as “repeaters”). What’s not to love?

Well, a few weeks ago, my wife and I rose from bed for our morning political fix from MSNBC, recorded on our DISH DVR. Not a single TV in the house had a DISH signal -- just the dreaded blue screens signifying that none was receiving a usable signal.

No problem, right? Obviously, the predicament wasn’t caused by a TV, because all six sets were showing the same blue screen. Must be a source or repeater that needed a hard reset. Our Integra DHC-9.9 A/V processor wasn’t getting a signal either, so I checked the Accell 2x8 HDMI switcher/splitter. It was frozen in the off position, which made it the likely source of our woes. But Accell’s tech support was language-challenged, and the only solution they offered was for me to return the unit. I replaced it with an Octava 4x4 HDMI switcher. The screens were still blue.

This made me think the villain was probably High-bandwidth Digital Content Protection (HDCP), the entertainment industry’s system for preventing digital copying of content. The lack of consistently dependable HDCP “handshakes” between A/V components is well known, and the fact that nothing was working made me believe that something like that was shutting down my whole system. I even tried recommendations from anonymous advisors on the Internet, who suggested specific and tedious solutions involving detailed ways of verifying and forcing handshakes in certain magical sequences that were often contradictory. I felt I was descending through the Nine Circles of Hell.

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