Originally Posted by giomania
I just wanted to post an interim update on my situation. I learned my existing 45-foot HDMI cable had an apparent maximum capability of 4K/30, as that was the maximum I could see when testing the various resolutions using the Apple TV 4K. I know the Apple TV 4K has an automatic cable test option, but when I tried using it, I saw some brief flashing, then the screen went blank. I had to power-cycle the Apple TV to get a picture back. I have ordered a 50-foot Ruipro hybrid HDMI cable, and will test it before installing in the conduit. I just didn't see the point in continuing until I know I have a solid cable run that works in excess of 4K/30.
I took the advice to simplify, but there has not yet been conclusive evidence of any particular device at fault. Frankly, it is very frustrating, but I also created a spreadsheet to track my testing, as it was getting too confusing. Once the new cable is installed, I will continue with the testing.
I thought my matrix switch was defective due to its inability to pass through [email protected]
Hz, but it turns out it was just incapable of providing enough power (5 VDC, 50 mA) for my Ruipro 50-foot hybrid fiber cable. I purchased an HDMI voltage inserter at the source end of the Ruipro 50-foot cable, and the Apple TV 4K works fine through the matrix switch, and prompts to "Enable Dolby Vision". This device was simply the easiest to test, because it automatically tests the HDMI video path capabilities when it is restarted.
After Monoprice ignoring my support ticket for two weeks, I called them. They said they switched to a new computer tracking system and were behind on emails. I explained the situation in detail, and they are clearly knowledgeable techhies. They had me perform some troubleshooting, including various EDID settings and connecting only one source and one display. They stated that sources can sometimes cause feedback that prevents the switch from working properly. There was no change in the behavior of the switch, so I called them back and set up the RMA, but they were out of stock until late September.
While waiting, I started thinking about what I could do to try and force EDID, in case the switch was not at fault. I started following along in the HDFury Vertex thread, as that device can force EDID. One of the users there has the same Ruipro 50-foot hybrid fiber HDMI cable, and a Vertex, and he posted about issues he was having. One of the troubleshooting steps recommended by Vertex support was to use an HDMI voltage inserter, because he said those types of cables have a chip inside that usually requires external power, but the manufacturers don't provide those to keep costs down.
I looked them up, and they were $10, comes only with the cable, no power supply, so I figured that is cheap enough to try it out. It came yesterday, and I used one of my extra Amazon Fire HD tablet power supplies (5 VDC, 1.0A), and boom, it worked right away with the Apple TV 4K. I still need to finish testing with OPPO UDP-203 and the Nvidia Shield, but at least I know the switch works and those sources may just require more settings, EDID tweaks, or yes...cable changes. Note that I had set the switch back to the default EDID (passthrough video and audio) during the final testing, so I just might need to play around to coax the other sources to send 4K through the switch.