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

[Shimmany]

I really want to pull the trigger on a Q95T here in Australia but all these bugs I’m reading are scaring me off majorly.. does 1402.7 firmware update fix anything? Such a shame as it could be such a good set! 

[Muzzakus]

Too much of a gamble it seems.   And even if good, they could bring out an update improving 50% of sets out there, but destroying yours.  They must have various panel versions or components from all sort of manufactures, but tune firmware once.  Works for some, does the opposite for others.  Joke of a situation, no QA. 

[Gökhan2]

Some users set the sharpness section to "0" in the image settings, wouldn't that blur the image?

I set the sharpness setting to 9, my tv model is 55q80t

????

[AV2020]

No, sharpness you want as 0. Sharpness setting is bad and artificial processing. Google it. 

[QuantumP]

Stay on topic! This is unrelated to topic. Make another thread. 

[daparky]

Can we please close this thread as the dimming bug has been resolved.

[SidL]

But the bug of local dimming in game mode with GMP OFF has not yet been fixed

[DUSKTILLDAWN]

Neither has the extremely dark vrr on Xbox,or the horizontal faint lines when GMP is turned off.

[SidL]

Is this only on Xbox? I haven't tested it on PS4 yet

[Aes28]

It's not only in game menus. The brightness or colors in a scene can make it easier to see, and as Toejo78 said, a grey background helps bring it out.  But, I personally notice it more often in blue- or green-dominant screens. I'm partially colorblind though, so that could play a part.