I found the smart reason why my TV screen was going black all the time ‣ Diverse Daily

I’m going to be honest with you — something I struggle with, occasionally, is the risk of painting a rosy picture of a technology that actually has serious flaws. I’ve said, for instance, that Dolby Vision is considered the gold standard for HDR, which is true. At the same time, a lot of people find its default mode too dark. It’s impractical to mention both things every time I talk about the format, so depending on the article you read, you might alternately get the impression that I’m on Dolby’s payroll or that I’m not-so-secretly championing HDR10+.

Chalk this piece up as another attempt to avoid rose-tinted glasses. In some situations, you may have noticed that your state-of-the-art TV briefly goes black while it’s loading new content. That’s annoying at best, and at worst, you might be convinced that you’ve got broken electronics on your hands. The truth is more benign, and thankfully, there are workarounds in some situations.

The truth behind HDMI blackouts

An inevitable consequence

In the olden (analog) days, TVs didn’t exercise much control over their content, or vice versa. You were simply tuning in a non-stop antenna or cable signal, or perhaps a VCR, and the most you could do was fiddle with a few buttons and knobs to adjust color or clarity.

The digital era is far more complex. Essentially, each video is presented with its own resolution, framerate, and HDR specifications, which your TV and/or media streamer has to accommodate as best it can. This can be extremely important — if there’s a mismatch between refresh rate and framerate, the result can be artifacts like screen tearing, and unusual resolutions can trigger unnecessary stretching or upscaling. You may have seen this botched stretching if you tried to connect an old 4:3 game console (like the NES) using the cheapest possible HDMI adapter.

To get things right, your TV can switch modes when prompted. For a Blu-ray disc, your TV might recognize not just that it’s in 4K with Dolby Vision, but that it needs to switch down to 24Hz from its peak performance of 120 or 144Hz. A moment later, it might flip to 1080p30 SDR once you decide you’d rather watch the news than that intense horror movie you bought.

The drawback to this mode switching can, as you’ve guessed, be a black screen. It’s usually just a second or two, but it can be disruptive for some people — especially if it happens several times in a matter of minutes. That’s a distinct possibility, since even the homescreen on your media streamer may be operating at a different framerate and HDR format than the apps it’s hosting.

This issue is sometimes known as the “HDMI bonk,” which points to another fact — you probably won’t see it when you’re using a TV’s native apps. When content is being handled directly by your TV, it’s fully prepared for each change. There’s isn’t even an HDCP copy protection handshake. Blackouts happen because an outside source is asking your TV to suddenly shift gears, and it doesn’t have anything to show until it can match a video’s formatting.

What can you do to stop HDMI blackouts?

Your options will vary

Chances are, the HDMI device you’re using has options for whether it will match framerates, dynamic range modes, or both. On an Apple TV 4K, for example, you can go to Settings -> Video and Audio -> Match Content and flip the appropriate toggle(s). Realistically, I can’t cover the instructions for every HDMI peripheral out there, but this should give you a sense of what to look for when probing a device’s settings menus.

By disabling this matching, you’ll reduce or eliminate blackouts, although there is of course a price to pay. I’ve already touched on the consequences of framerate mismatches. If you don’t sync HDR modes, you may in some cases be stuck with SDR. You’ll be fine if, say, both your media streamer and the content you’re watching are set to Dolby Vision. If that content is HDR10+-only, however, and your streamer is still locked to Vision, your TV won’t be getting the necessary metadata.

Thankfully, all of these issues should eventually fade into history. HDMI 2.1a introduced a feature called Quick Media Switching, which taps on another 2.1 technology, Variable Refresh Rate. VRR syncs refresh rates to framerates, so when an HDMI device needs to flip between 24, 30, or 60 frames per second, it can do that without any visible delay.

There are a couple of catches to QMS, the biggest being that resolution and dynamic range aren’t addressed. In that case of switching from 4K24 HDR to 1080p30 SDR in the last section, there would still be a blackout, even though refresh rates were taken out of the equation. The second is that your cable, device, and/or TV port all have to support HDMI 2.1a or later, and that’s a problem when manufacturers are still trying to get away with including 2.0 ports, never mind updating everything to 2.2.

My advice is to leave content matching on regardless, unless you care more about convenience than seeing a movie, show, or game the way it was meant to be displayed. Convenience is a legitimate demand — if all you’re watching is the news, there’s no reason to put up with HDMI bonks whenever you launch or leave your streamer’s main page.