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

[Suriya]

yes but for 1 hour its not happened but just now it did happen again. Even tried with double fan to confirm. So deleted the post sorry guys.

[Suriya]

Because of the ST.2084 gamma 2 adjustment it is hard to note the dimming but its happening like before nothing changed. It is definitely an software/firmware issue.

Really sorry to mess it up guys

[RouDeR]

ALL modes HAVE this problem on my Q800T when PLAYING games,
the picture dims randomly if I use Local Dimming on High.

[Alekkk]

OKAY then. Seems like you’re having a go at me, but I don’t know why. I was replying to someone suggesting this is an overheating (hardware) fault; I’m saying it’s a software fault. Rather than each other, how about we get angry at Samsung instead for their total silence on this, for not acknowledging the issue and for giving us no indication they will ever fix it.

[LCDeez]

It’s definitely software. You can put game motion on and set dimming to high and it won’t happen. You can turn it off and play 10 minutes of a FIFA match and pretty much dead on with timing each time, it dims. Heating failure would be more random. 

[OhThatOneGuy]

Hi everyone, in response to jdk2087 no I have not heard anything more from the engineer in 8 days. I emailed today him asking for an update, I'll be sure to let everyone know if i get a response.

[SeeNoWeevil]

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@Suriya wrote:

In game-mode yes exactly local dimming got worse more blooming and grayish 

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This is exactly how it is on the 2019 Q90R and it went completely unfixed (I believe the 2018 Q9FN is also broken). If by the slim chance any engineer is reading this, pleas, please also spend time on improving HDR game mode on the Q90R. It's terrible.

My first 2 Q90Rs also had terrible inverse ghosting in game mode.

[Suriya]

Definitely no engineer is going to read this or even the irresponsible moderators also not going to inform anything we're just a bunch of fools spending our priceless time with worthless team from samsung. Better move on to some other brand. 

[Suriya]

Can anyone pls check playing FIFA with Dynamic black equalizer +2 and all HDR game-mode All default with game motion OFF and pls let me know the dimming bug is happening or not. I don't have FIFA and it seems with dynamic black equalizer the bug happens lesser and randomly on my q95t but not frequently on other games without constant brightness on screen

[jayh89]

The moderator @AntS  has informed the tv team. It’s a matter of waiting now.