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

[callisto92]

A LOT of comments here. Signed up just to say I returned mine due to this. Game mode looks awful on the PS5. Samsung are clearly aware of the complaints, yet have chosen to remain silent. The only effective action is to speak with your wallets and not give them your money. 

[peterQ95T]

I must aggree this TV sucks bigtime. i was watching a movie last night with subtitels and every F***ing time the TV Dimmed the picture when subtitels was changing  so anoying. this only appears when the subtitles is above the blackline directly in the picture. Im on latest Firmware 1403.1 and my Set is a Q95T &5 inch European model. Samsung dosent care ***** about these problems because they only think 8K that we all really need right now with so much content(sorry i'm so disappointed) 

[brook1]

This is disappointing indeed not even a statement from Samsung assuring us that they are working on a firmware to fix most of the issue they are ignoring us i swear i'll wait for some time then if nothing i'm going to return my q95t and never ever going to buy any Samsung product i can't deal with this anymore they literally gave me anxiety i spent so much money on this tv and i've never seen a tv with this many issue and no response at all why are they taking their customers for guaranteed ?!

[Danboy76]

I am in France and we have a two yr guarantee over here. I have had my Q80t 4 months now, and my intention is to wait until the spring to see how this shakes out. I am already sick of the DSE everytime the camera pans and I have had the dimming a couple of times. But a lot less than others. And I am always keeping an eye out for it.

In the spring, next yrs tvs should be out.... Just the DSE alone is totally unacceptable for a 1300 quid tv. It is a shame because even on this set the HDR pops nicely, and the colours are great for gaming (I like a lot of colour when I game).

[martinsfail]

Meanwhile I have the problem that the game mode turns on and off in the middle of the game. Anyone else?

[QuantumP]

It seems with the latest firmware update that has caused a new issue with dimming at random:

Anyone got a dimming bug when watching HDR content on Amazon Prime Video? The screen dims after a few minutes and I have to exit the app and go start it again. It is like the HDR dims/turns off after a few minutes.

I heard there was a game mode dimming bug, that was fixed but now there is a dimming bug on the inbuilt apps?

[MvdLaar]

Hey, looks like I have something similar going on in built-in apps like YouTube and Netflix on the latest firmware. Does your problem give you something like this? https://eu.community.samsung.com/t5/tv/q95t-local-dimming-not-adjusting-after-booting-up/m-p/2290653...

[horror_x]

I have another problem with dimming on Q90T.

In TV mode or during watching video using apps like Youtube, when most part of screen becomes black (for example on text or small/dark logo on black screen, credits, etc.) all other colors become dimmed with little delay (for example, bright white text becomes gray or even dark gray).

It seems like brightness adjusted to average black/white balance on the screen. Such brightness fluctuation looks awful and breaks my eyes (and mind).

All possible related settings are switched off, firmware updated to 1403 via Internet, factory reset after update was performed.

[minigibby2212]

I've got the 75 inch Q80T. I'm in the U.S., but I've been having issues with weird backlight behavior in certain video games, regardless of game mode. The worst example so far is Spider-Man Remaster on PS5. Every time I pan the camera around, the lighting shimmers and dims, and then stops when the camera stops moving. Super distracting on a fast moving game. Had the same issue on Watch Dogs Legion on the Xbox One X. Tried with HDR off, tried with game mode on, game mode off, GMP on, GMP off. Will not go away. So frustrating. 

[daparky]

Have you got a video?