2020 QLED T models (Q80T, Q90T, Q800T, Q900T) HDR game mode brightness / local dimming bug

[Rauttis]

I bought a Q80T a couple of days ago and have noticed a really annoying issue when using the tv with the combination of HDR and game mode.

I'm fairly certain this is a software bug in the TV since I can reproduce this issue with 100% accuracy, and it happens on the dot at the same moment every time. It's basically on a timer.

Basically when the game is displaying a HDR signal and game mode is enabled, exactly after 6 minutes the brightness of the TV suddenly drops by around 20 (50 -> 30). The value of brightness setting doesn't actually change however. Messing with the brightness setting does not restore the brightness to it's original state, but changing the local dimming setting from standard to low and then back to standard does. Switching game mode off and then back on also fixes the issue, but then it happens again EXACTLY after 6 minutes (I've timed this with a stopwatch).

Has anyone else experienced this issue? Or can someone maybe test this on their TV to see if you can reproduce it?

Exact repro steps on how I can reproduce this 100% of the time on the PS4 Pro:

1. Set brightness to max (50)
2. Set local dimming to standard (bug happens on high as well)
3. Enable game mode
4. Turn off game motion plus
5. Turn off intelligent mode and all the brightness related settings in eco settings, as these can influence the brightness level of the tv.
6. Launch a game that runs in HDR
7. Start your stopwatch
8. Do whatever you want in the game or you can also go back to PS4 menus, find a bright scene where you can notice a brightness drop easily
9. When the stopwatch hits 6 minutes, you should see the TVs brightness suddenly drop by a large amount. By eye the brightness drop seems about equal to dropping the brightness from 50 -> 30 by hand.
10. Go to picture settings and set local dimming to low (brightness does not change)
11. Set local dimming back to standard (brightness suddenly jumps to the original level. Brightness can be restored by switching input away and back as well, or by disabling and re-enabling game mode)
12. And again after EXACTLY 6 minutes the bug again repeats and the brightness drops down again

Some other notes: The PS4 has a screensaver that basically dims the screen if it is idle for a while. This is not the cause of this, this happens even when the console is in active use and the brightness can be restored temporarily by changing the local dimming setting like described above. I have not managed to reproduce this issue with game mode off, so it seems to be related to game mode.

Software version: 1304

[Toejo78]

I'm thinking of doing the same, still in my return period. It's just not good enough, updates make or break hardware and European customers clearly aren't a priority for them.  Happy to take our money and leave us unsupported.

[jayh89]

I think it's more than they have to make some changes or final checks for EU version. I guess some things are slightly different between EU and US. The update will come soon, I hope. 

[De-mon]

I am going to keep this TV once they launch the firmware in Europe and deactivate automatic updates. If it works fine, I won't update further until I make sure no new issues appear.

Of course it has been a bad consumer experience and I will not trust the brand so much going forward. I don't usually do it blindly, but this television was good for its characteristics; I just hadn't investigated this bug. I have learned my lesson and not everything is to trust technical data or review sites. Today an update can make a product worse that was good before.

[Smooky]

Yeah that's true, this update seems to have fixed the bug for now but I just don't feel confident with their software updates. The dimming bug was introduced with an update in April I believe, we are in October now, can't believe it took them half a year to fix it. This is just not professional! If you happen to buy the X900H, make sure to turn off A/V Sync in the audio settings when in game mode. It's on by default and increases the input lag quite a lot. When you have it turned off, the input lag is very low, around 14ms so on par with with Q90R from last year but game mode generally looks better on Sony TV's as they don't completely turn off image processing. Let me know if you have any questions about the X900H, I will continue to test the two TV's side by side for another week and decide which one to keep, but for now I think I'll stick with the X900H.

[Smooky]

I would do some further research on the automatic updates thing if I were you. Someone on reddit was complaining that the updates installed even though automatic updates was turned off. The guy literally had to blacklist his TV from the router in order to stop updates. Personally, I've never had mine turned off so cant confirm if thats the case.

[SidL]

Pode confirmar isso cara? Também sou do Brasil

[WackyHackster]

I'm in the US, Q80T owner, just updated it last night and know plenty of users on the AVSForums that have as well. Make sure to follow the steps for putting it on a USB correctly, there is an install file below the actual firmware file on the support page.

[jayh89]

Sadly we can’t. It’s not out in the EU yet 😞 Matter of waiting...

[De-mon]

What a joke, but thanks for the warning.

[Suriya]

Samsung guy said update will roll out in a week. and I'm not able to get q85t eu update file.