The background

I recently got a Philips 65OLED708 TV, based on Google TV. Gorgeous large screen, bright and vivid. And since it's Google TV, it also has an "ambient" mode that can display, among other things, photos from Google Photos. And I have plenty of those, so on the previous TV Chromecast did a good job displaying that.

"So far so what, but here's the thing"

The damn thing starts displaying black screen with white Philips logo jumping around after two minutes of inactivity! And there's no way to set longer timeout or disable it in conventional settings, because they decided to safeguard users from OLED Burn-In. So much for using the beautiful screen for anything apart from watching videos... Now, Ambient mode has elements that can remain at one-ish place for a significant time (weather, time, album name), but unlike that pesky Philips screensaver, they can all be disabled to leave just constantly changing images which would NOT cause burn-in.

Luckily, there are ways

After some googling, I found two reliable ways to do it - one (hopefully) more permanent, and another temporary but with more access to the system.

The (seemingly) permanent way

is to revoke the "Display over other apps" permission from the "Tv System UI" app, by following this path in TV menu:

• Settings
• System
• Storage
• Internal shared storage
• Apps
• Special app access
• Display over other apps
• Finding "Tv System UI"

and disabling it. It still triggers (there's a temporary notification when it does), but it doesn't overlay the Ambient mode slideshow anymore.

The temporary way, on TV

is to stop the Tv System UI app by navigating to:

• Settings
• System
• Storage
• Internal shared storage
• Apps
• See all apps
• Scroll to the bottom to find "Show system apps"
• Scroll all the way down to "Tv System UI" (NOT "System UI")
• Force-stop it

It will come up on system restart though. And it's A LOT of scrolling.

The temporary way, on remote device (OSX laptop, in my case)

is unnecessary complex, but I'll leave it here in case I'd ever need to do more with the TV, as is provides a way to connect to its internals with Android Debug Bridge.

First, installing ADB:

• Install homebrew
• Install adb: brew install android-platform-tools and check that it's available with adb devices (result would be empty for now)

Then (from https://www.reddit.com/r/Chromecast/comments/s96moi/how_to_connect_to_ccwgtv_via_adb_using_only_wifi/):

• Find your Google TV's IP address and write it down to use later. Go to Settings > System > About > Status. Your IP address will be something like this made up example: 192.162.3.4 (ignore the long number that you'll see above the IP address).
• Enable Developer Options on your Google TV:
  • Settings > System > About.
  • Scroll down to “Android TV OS Build” (Make sure it says BUILD not VERSION).
  • Tap seven times. You’ll see a message that says you’re now a Developer.
• Enable USB Debugging on your Google TV:
  • Settings > System > Developer Options (if you don’t see this, then the previous step did not complete successfully)
  • In Developer Options, ensure Enable Developer Options is toggled on.
  • Scroll down to USB Debugging and toggle it on.
• Make sure your Google TV and your computer are on the same WiFi network.
• In shell, run adb connect [your Google TV IP address from Step 1].
• On the TV, you'll see a message like this: "Allow USB debugging?"; allow it (with TV remote).
• Back in the command window, you'll probably see something like this: "failed to authenticate to 192.162.3.4". That's OK - if you try e.g. adb connect 192.162.3.4 again, it'd say "already connected to 192.162.3.4"
• To check that you're connected, list the connected devices with adb devices - should be e.g. "192.164.3.4:5555 device"
• To disconnect (when needed): adb disconnect 192.162.3.4. Reconnection would require confirming it on TV again.
• Run adb shell am force-stop org.droidtv.tvsystemui

That does pretty much the same as what could be done manually - benefit is, it could be done faster than in UI once everything is set up, and ADB would allow a lot more if needed.

Tada!

Here's one of the photos to emphasise the importance of having the ambient mode: