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

[HQboy]

Yes, English is not my native language and I don't speak it very well, sorry about that. The important thing is to understand the message, right? That matters. Or are you going to be preconception against me because of my English?

I try to talk about a problem common to all of us anyway. You were reported.

[jayh89]

This thread is a joke now. It’s a shame because I think it really made a difference in the start and Samsung did take notice. Most of us say the dimming bug is gone. This thread should be to confirm that,  it argue over settings or troll people. 

Can people confirm they have or don’t have dimming? Some mention other VRR issues such as verticals lines? 

[QuantumP]

No dimming here. Xbox One X running VRR. Perfect picture.

[Danmay]

I can confirm no dimming bug since the update. These 'scrolling lines' for me were most easily visible on any light colour. Try putting your screen to a full grey colour with GMP and VRR off, that's where this issue will be most visible if you indeed have it at all. 

[QuantumP]

Can everyone just stop arguing. Go and play a fighting game or something to take out your frustration.

[DUSKTILLDAWN]

Don't bother these guys are a joke , according to them they have the perfect TV ,no issues ..mmmmm

[QuantumP]

Someone is moody they have a faulty tv. Shame. Q95T owner here and no issues apart from random stutter as discussed in other thread.

[Danmay]

Well keep in mind sometimes TV manufacturers will use various different sources for panels/chips. It may be some have an issues and others don't. It also might be that some people simply cannot 'see' the issues. The point of this thread is for people to discuss the issues they have discovered right?

[Soccercrazy1]

I posted earlier but it got covered up by the arguing.

I said the same thing as you, vrr (on Xbox at least) gets very dark and the colors are very off. It looks like a little kid played with the white balance as to how bad it is. 

I do not have the scrolling lines issue whether GMP is in or off. I do though have the US version of the q90t. It seems that the US has been getting the different software in recent updates. 

There is slight motion smearing as well with GMP off but you really need to look for it. 

I to was going to return this tv before this update fixed many of the problems in the US. If you are going to use the TV primarily for gaming, I also have a Sony 900h and it is a great tv. I recommend you give it a try if your primary use is gaming because it has great motion and game mode uses it's full local dimming. It's ok in content outside games but no where near the 90t. If viewing angle are important as well then the Samsung is the only way to go for LED.

[DUSKTILLDAWN]

Finally someone who actually notices a current issue that may effect everyone,even the ones to blind to see this issue,scrolling horizontal lines which are seen with GMP off and in freesync ,yet we continue to argue about settings,if your TV is fine why you on here