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

[Toejo78]

I had the scrolling lines on 1304 q95t still there on this update.

[jayh89]

Think I agree with most of this. I think sometimes we expect too much of a TV. I know it's expensive but it literally cannot be perfect and will always have something to be improved upon. Also, HGIG doesn't appear to dim my picture, it makes it brighter if anything. But then again, that isn't the point. It's about giving more accurate HDR results that the game developer intended. Keep in mind not all games are HGIG compatible (I think). 

Additionally, I am sitting here staring at my PS4 Pro screen with a game on and I cannot replicate the dimming issue. I am 95% sure it's gone. 5% of me in anxious that I'm missing it haha.

[DUSKTILLDAWN]

You on PS4 or Xbox

[Vagval13]

I have the 49 inch version so 60hz panel no port hdmi 2.1 so no difference where you plug in the console. 

[DUSKTILLDAWN]

I appreciate your comments but on my Q90T with GMP off and freesync off I get scrolling faint lines in Xbox grey background ,with GMP on there gone but pic is darker ,and at the moment hgig just looks darker because I'm running GMP and hgig to remove scrolling on dash ,cable is certified came with my project Scorpio,and console tested on q60r:doesn't have these issues but q90t does after 1402.6 .freesync is to dark to game it's a joke,and all ports are behaving similar just tested.

[SidL]

Suriya provided a link for a 1402."7" firmware and the official is 1402."6" who installed this firmware that he made available, is ***** up. It will not be possible to install the official.

[SidL]

And the local dimming? is working properly with GMP OFF?

[jayh89]

Hope they fix any VRR issues before the next generation consoles come out. Also, do people here use the dynamic black level equaliser? What number setting?

[swko]

My version in North Africa and I think some asia countries as well latest version is 1402.7 so now you know where he gets his stuff from 

[DUSKTILLDAWN]

Can't tell as standard looks same as high in game mode ,and if I turn GMP off I get faint scrolling lines on Xbox dash which gives different Impression.