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 agree picture is better and HGIG is a great addition. The brightest changed quite a bit on COD between standard and High for me on 1304 and doesn't now.  Like I said standard is plenty bright enough anyway. Regardless if its not as bright or not at least it's now consistent and not annoying! Which is all that matters.

[Keitoki]

it was not the real Suriya just a fake by AV2020...

[Toejo78]

Oooh ok, I missed a bit in the middle too many posts lol

[DUSKTILLDAWN]

So are people now gaming with game motion plus off now?I mean no more need to keep it on ,with 1 notch to restore colour back,if you guys are has anyone vtrird freesync HDR ,is it dark like before at work so will try it later in UK.

[jayh89]

I never used GMP even before this update. I really don't see what it does to improve games unless you use the blur reduction or judder reduction. I didn't use either because I think they make games worse more often than not. 

[Toejo78]

I play with it off when input lag Is paramount, for single-player games I leave it on for better image quality (on those it improves).  I didn't notice it being dark on freesync HDR, what was that on (Game/ Machine)?  I will see if i can test it.

[Toejo78]

I agree I think it entirely depends on the game.

[jayh89]

Do you think GMP improves the image much? I can’t really see much change on Tsushima for example. 

[DUSKTILLDAWN]

Vrr feature turned on Xbox gives you freesync HDR which was very dark on t series q90t,but not on last year's r series,when I got TV it updated to 1304 on that day ,but vrr stayed dark ,and with game motion plus on it stopped the brightness fluctuations but lost some colour which is why game motion was moved a notch to restore colour,with vrr on Xbox it puts freesync HDR on and turns game motion off,but turning both off caused bright Ness issues hope they are better when I return home ,keep checking guys all feedback to each other is good no argument s though.

[Toejo78]

Don't have ghost yet was saving it for the ps5.  I think it reduces ghosting when you are playing FPS games, Colours slightly improve I think on some titles, but then you gain input lag, I think you can see it more in dark areas.  My kids play Fortnite and you can tell in the woods when its dark.  It's definitely clearer with game mode on.