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 will give that combination a try tonight and see.

[Jihionfly]

Do u guys think a factory reset after the update would help in any way?

[DUSKTILLDAWN]

Vrr on Xbox one X on ,warzone HDR on ,so display shows freesync HDR I brought up guide to see whos online ,and can tell that even running dash with vrr setting on it was way too dark on q90t,on a family members q60r from last year with vrr and freesync on HDR was brighter,and should not be brighter than the q90t with same settings so I knew it was messed up on 1304,

[Mordechai]

55" Q90T EU-Version here - just Updated - dimming bug is still there for me

GMP and HDR Enabled - Dimming happens. GMP without HDR - no dimming. Input set as PC.

Great Work Samsung! I am so incredibly proud of you. 🤣

[NickHwd]

Seems to be working OK on my UK Q95T. I can't select HGIG though (says it's not available and is greyed out). I wonder if it's because my Xbox and PS4 are connected through an HDMI switch. That doesn't affect game mode though. Weird.

The big issue for me was Atmos dropping out over eARC so that's what I'm testing at the moment. I'll report back on that later...

[Iskandarkebab]

Hgig can only be activated while reproducing HDR content. So you should do It while playing a HDR Game ir at the HDR setup in the PS4 menu.

[NickHwd]

Ah - thank you. I'll give that a try.

[AV2020]

Guys remember once you have  enabled Hgig games nto HDR calibration on your game console like ps4 or xbox and calibrate HDR settings on the console. They are like checkerboard blocks that you calibrate to the right settings.

On another note,  would you say the general picture quality for normal HD has improved? 

[NickHwd]

Thank you - that solved it. Completely obvious (when someone points it out!)

Atmos passthrough going well so far. But it was on and off under the previous firmware so I'll keep testing.

Now all I need is for Microsoft to fix the Xbox dolby audio delay over HDMI. The next console generation can't come soon enough...

[jayh89]

Possible that PC mode still had dimming bug. Can everyone else confirm it is gone in game mode??