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

[Suhorukow]

Hello. What is it gmp ?

[JAMES4578]

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@Suhorukow wrote:

Hello. What is it gmp ?

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Hi @Suhorukow  It is Game Motion Plus  https://news.samsung.com/uk/infographic-made-for-winning-gaming-on-qled-tv    Could also have a look at this  thread https://eu.community.samsung.com/t5/tv/q80t-q90t-game-motion-plus-with-hdr-bug-issue/td-p/2189762 

[Snir4]

Hi I am hesitant to update version, today I am with 1947. I am trying to update via usb I downloaded the new version 2014.1 from the official website of Samsung uk I extract it according to the instructions try to do "update now" he asks me with search in usb I tell him yes and he writes me "No new versions found for you" I have never had a problem doing this before. Samsung q95t

[Suhorukow]

Thanks

[DGrooV]

After update to 2014.1 local dimming is going bizar on my 80T. 
https://us.community.samsung.com/t5/HD-and-UHD-TVs/Firmware-2014-1-bugs-on-65-quot-Q95T-QLED-televis...

[DGrooV]

After the 2014.1 update Local dimming seems to be way off and strangely fluctuating in dark scenes in combination with bright objects.

[SidL]

On my Q95T 55'' after the 2014 update, the local dimming with GMP DISABLED has improved a lot, which is how I play because with GMP ENABLED it looks horrible. Because before updating with GMP DISABLED local dimming was completely disabled. I just hope that Samsung doesn't try to fix this and go back to being **** like it was before.

[Peto Pedro]

Simply turn off ll energy saving S**T

[MrBourne1]

Who is he? Samsung is not a man 

[DSchaf]

I found an interesting setting in the "hidden secret service menu" of my Q90t:

Option > Production Option > PC Mode Dimming Support > OFF

At least I hope this is "the fix for gaming mode". I did not immediately write down what I changed and had to recollect this setting from my memory.

If this really is the setting I changed some weeks ago, it will disable the HDR brightness pumping that so many of us are plagued with. Take a look at "PC Mode Dimming Support" and change it to "OFF", when it is set to "ON" on your TV.