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

[jayh89]

I see there is an update out. But I think it only adds filmmaker mode. Can someone confirm?

[KindOldRaven]

This is the patch that adds filmmaker mode, but also fixed inverse ghosting on the american Q90Ts and improved game mode visually. So perhaps it'll do that here too. Please note it wasn't exactly mentioned there, but users figured it out pretty quickly. Just youtube the issue and you'll see!

[jayh89]

Have you got any links?  

[jayh89]

I just played some FIFA to test it and this update has not fixed the problem. I didn't think it would considering it hasn't even been 2 weeks since they were notified of it!

[KindOldRaven]

EDIT: I need to get some more coffee, I thought I was replying to a different thread on this TV here >.<',, 

I'll pour this into my e-mail/phone call I'm hoping to have with someone at Samsung. Fingers crossed I don't get stuck on the ''level 1 service employee'' who probably won't know what I'm talking about.

[jayh89]

I just watched the video and he only mentions inverse ghosting, which isn't the problem we are all suffering in this thread. What we are seeing is the whole screen dramatically dimming after 5/6 mins of gameplay in HDR. A mod on here has escalated it to Samsung so a fix is coming, we hope! 

[LCDeez]

In the US here, the patch didn't fix the dimming with Standard or High LD. 

[RouDeR]

The overshoot in Game Mode (without GM+) is still present,
The Dimming issue is still present as well on my Q800T with the latest 1302 update

[KindOldRaven]

Okay this is getting downright weird now. I've seen tons of reports that at least the inverse ghosting was fixed with 1301.5 in the US. Then 1302 releases in the EU and nothing's changed except filmmaker mode got added?

[Suriya]

We have to make a petition against samsung about this game mode dimming issue. Or we all together return the unit directly to Samsung under manufacturers defect and go for lg cx that is the quicker end for this.
Never expect this from a company like samsung really disappointed