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HDMI Connection Fail

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Jim Firth:
Recently an HDMI connection we've been using for years suddenly and inexplicably stopped working. After trying different Mac ports, dongles, and even different Macs, our troubleshooting seemed to point to the HDMI cable itself. While we are a mobile church that sets up and tears down each week, the projector we use is permanently installed in the building and the HDMI cable feeding it is permanently affixed to the projector. (It doesn't get routinely plugged and unplugged on that end).  So if the HDMI cable is the culprit, it seems to be failing only on one end. We experimented with different HDMI cables and found that not all HDMI cables are created equal. There seems to be a significant difference in quality as many of them didn't work at all, even when changing the directionality. The distance between the source (a Macbook Pro) and the projector is about 15 feet.  We only had a couple spare cables long enough to make that run and neither worked. One was 25' and the other 15'. We finally found a solution using two shorter HDMI cables and ran them through an HDMI to Cat 5 converter, even though the distance was only 15'.  Not ideal obviously.  Strangely we were having the same issue with our stage display, which also uses an HDMI to Cat 5 cable to make the 100' run down to the stage display. (We purchased a second HDMI to Cat 5 converter this past week just in case that was the culprit). We were able to solve the stage display issue by using a different 3' HDMI cable from the computer to the converter. (The cable on the other end is hard wired to the display).    So my questions are: Is this a common problem? Is there a recommended brand of HDMI cable? And, what is THE most stable, reliable, professional connection possible? (SDI?) I can't imagine if budget was not a consideration that HDMI cables would be used.  I am VERY interested to know the very best connection possible between a computer and a projector, and between a computer and a stage display. Thank you in advance!

Brian Jojade:
HDMI is a nightmare protocol for live work.  The connections are extremely fragile and cables more than a few feet long can become unpredictable.

Of course, that won't keep people from trying it over and over, even if it fails on them. 

SDI would be better, but there isn't much gear that has it built in, so now you have to deal with converters and whatnot.

Jean-Pierre Coetzee:
All connectors have a set amount of cycles that it can endure. The best option is to put a female to female adaptor on it and connect a short HDMI cable to that, then when the adaptor wears out you just change it out in-stead of the entire cable.

Tim Hite:
HDMI is useless for anything professional where reliability is a concern. Just the fact that it's a non-locking connector is proof enough of that.

On the low end, you can more to HDBase-T. Monoprice has some very reasonably priced hardware that works fine.

Otherwise move to the appropriate flavor of SDI. 3G-SDI will do 1080p over a single piece of 75Ω coax. The Decimator MD-LX works very well, and they are USB powered so the device can power the converter. AJA is the high end brand, if money is no object. Black Magic is the other low-cost option. I have been warned to stay away from the micro converters and stick to the mini-converter line from Black Magic. Everyone I know frowns on the $50 china generic SDI systems.

Caleb Dueck:

--- Quote from: Tim Hite on March 03, 2020, 01:58:03 pm ---HDMI is useless for anything professional where reliability is a concern. Just the fact that it's a non-locking connector is proof enough of that.

On the low end, you can more to HDBase-T. Monoprice has some very reasonably priced hardware that works fine.

Otherwise move to the appropriate flavor of SDI. 3G-SDI will do 1080p over a single piece of 75Ω coax. The Decimator MD-LX works very well, and they are USB powered so the device can power the converter. AJA is the high end brand, if money is no object. Black Magic is the other low-cost option. I have been warned to stay away from the micro converters and stick to the mini-converter line from Black Magic. Everyone I know frowns on the $50 china generic SDI systems.

--- End quote ---

What Tim said.  Decimator MD-LX or MD-HX.  Overall failure rate of Decimator - nearly zero (one power supply).  Failure rate of Black Magic?  Up to 25% on one particular job.  Stay away from the cheap converters.  If you don't need HDCP, SDI is the way to go. 

If you're using a Mac with ProPresenter - check out the BlackMagic UltraStudio 4K Mini.  It's still BlackMagic, but you can bypass HDMI completely, has sync in, audio out to audio system, SDI out to projector.  Convert with MD-HX or MD-LX to HDMI at the far end.

Good HDMI cables are typically good up to about 35', sometime at max 50' but not worth the gamble, total distance from source to final display.  Some devices re-clock the signal, some don't, including lower cost HDbaseT extenders.  Good HDbaseT extenders and good cables - typically work great as long as you stay within spec, around 300'.  Extron, Atlona, and some brands from Liberty (DigitaLinx) have worked great.  Key Digital - not great, lots of failures. 

15' from computer to projector total, if that's true - should be easy for any decent cable.   

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