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

[Keitoki]

Bro can you stop spam you'r thread at every pages of this thread ? it's very annoying...

[Soccercrazy1]

Yeah sorry. It's just people started talking about it here when I brought it up and I don't want that problem to get mixed or overlooked because of this one. This thread is not for the local dimming so I didn't want that chat here

[QDguru]

So much for the firmware update LOL. I bought an X900H and the IQ is leagues better than the two Q90s I had 

[De-mon]

X900H was my second option for gaming, but I choose the Samsung because I didn't want to wait for the 2.1 HDMI firmware. LOL and then I see this firmware bug on Samsung TVs.

I really don't know when they will release the update, it is a major bug and I imagine they will. But I will also let everyone I know about Samsung product problems and their lack of feedback. Many people will buy new televisions to make the jump to 4K, I will recommend Sony, LG or any other brand.

Look, I can wait a month if Samsung gives an approximate date for the update. But until now they pretend this is a problem that does not exist and should not be known. Can't they communicate that "we're working on it" or something like that?

[Jihionfly]

Dimming bug happens also with gmp on.just happened to me now while playing horizon zero dawn on pc at 1440p 60hz on q90t model.btw gmp cannot be enabled at 120hz

[Mordechai]

GMP can definitely be enabled with 1440p 120 HZ (+HDR) on a Q90T - it’s how I Play Horizon as well . Maybe it’s already activated but the menu fails to show it correctly? 

[QuantumP]

Come on Suriya, what's the new date you are going to come up with now. 😂

[Keitoki]

31 sept 🤣

[QuantumP]

🤣🤣‌  Probably, then he will say wait a few days after. Then the next date 8th October. As his close contacts at Samsung have discussed with him the new date. 

[jdp117]

Hey did we ever get a fix for this? I've had my Q90T about a week and I've also noticed the exact same issue you're having in the exact same scenarios. We're now in late September and thought a fix would have been made available by now. Have Samsung released any more info on this?