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

[Jihionfly]

Is there a difference in local dimming (high) effectiveness with gmp on vs off? im not talking about the dimming bug.q90t

[HQboy]

Yes, when GMP on, localdimming is practically disabled. Try changing (local dimming)  its settings when the GMP is turned on and you will see that there is no change in the image

[soothsayer123]

Surely this kind of thing is against consumer laws in most countries? These TVs are advertised as having full array local dimming and a low-latency game mode, yet in reality these features are mutually exclusive. It's reasonable for a consumer to expect both to work simultaneously, as is the norm. That they don't work is a defect. If the product had been advertised accurately, I'm sure many of us would not have purchased it.

In lieu of any communication whatsoever from Samsung, and seeing as it probably wouldn't be economical to take out a class action lawsuit (like the one against Apple over their faulty keyboards), it might be worth reporting this to your country's consumer protection agency. For Australia, go to the ACCC. For Europe, there seems to be the European Commission. For America, I'm not sure. Maybe this will get some kind of resolution.

[HQboy]

I'm trying to play last of us 2 and this is impossible, even with GMP activated the image gets very dark every 6 min. It is already a dark game, when the bug happens it is unplayable.

The strange thing is that in some games, with the GMP on, the bug does not happen. Although the GMP already deteriorates the image quality a lot.

[daparky]

Is this not down to if the game has HDR enabled or not?

[Keitoki]

Where is our promised update ? 😞

[De-mon]

Someone said the bug does not happen on 60 fps games, like COD.

[Tv52]

The funny think is that this TV is still rated by many sites (even those respected) as best or best non OLED TV for gaming If you have time I would recommend dropping email to them asking for that.

[jayh89]

Playing Uncharted 4 and what’s so odd is that it dims, then the brightness slowly goes back to where it was before dimming. Then it dims again after X time. Repeat. Repeat. Repeat. It’s annoying as hell. Something needs to be done. 

[jayh89]

@Suriya Any updates from the people you speak to? I think they are totally bullsh*tting you now.