Review on 🔌 High Performance Flat HDMI Cable 20ft - 4K 60Hz, 3D, 2160p - Latest Standard - CL3 Rated by Brian Nelson

Bought a 10ft set of two about 18 months ago but didn't use it until this week. LG B7 OLED + Apple TV 4K + HDMI Ultra Clarity flat cable 10ft. Result: failure. Details: During the initial Apple TV 4K setup, the user will be asked if "Enable Dolby Vision" is required. Select Yes and the ATV4K will run a video test. During this test, the screen goes black for about 10 seconds. If you see pixel flickering or other oddities, it means the cable connection is not enough for DV. When the screen returns, the options "OK" and "Cancel" are also available. If the cable isn't enough, the GUI will automatically stop and the only option is 'Cancel' (happens automatically with a 20 second timer, you just have to sit and wait while it counts down). This is exactly what actually happened in my setup. Incidentally, the system uses HDR10 60Hz, which works great. I replaced the flat cable with a 10ft SecurMax cable (another brand I bought 18 months ago as a "just in case" option) and indeed it worked great for the DV test. Now I am very unhappy as I ignored the warnings from users here and ran flat cables through the wall under the name "they are more ergonomic" especially for the B7 with its HDMI on the side. . Now I need to pull out and replace these ribbon cables. As an EE, I have to admit that I was quite skeptical about this result. I'm still somewhat hopeful - I think shorter lengths of this cable, maybe 6 or 3 feet, would work well. My further guess is that the HDMI A4K output driver circuit is probably marginal when it comes to being finicky with cable impedance levels and/or the ATV4K has HDCP handshake issues. I say this because other reviewers have found the cable to not work at all (like me) or to work for minutes or hours and then suddenly fail and require a reboot. The problems must be related to the ATV4K itself.