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

[Tiayeahdude]

How can I check if my q80t suffers from the local dimming bug

[BogaMoge]

Simple :

- display any source (in HDR preferably, since the local dimming bug happens more, or more clearly in HDR) - a title screen for a game with some moving elements  is a good choice, as it's a fixed scene, but not completely static

- take a picture of the display

- wait for 6 minute (or a bit more if you want to be sure)

- take another picture (try to be in exactly the same condition)

- compare the pictures

Or, if you have the patience, just display the title screen of your game and look closely at the screen for 6-8 minutes and see if there is any loss of brightness.

But be aware that the local dimming bug does not happen to all the same way. For some, it's always there, for others, only in HDR, and even sometimes it's content related.

Be also sure that you have turned off all Eco Solution and Intelligent Mode settings (in Settings > General).

Good luck!

[BogaMoge]

For everyone with purple ghosting, if you have a tech or a Samsung rep that pretends the problem comes from your source and not the tv, open this video (at that timestamp) on your tv's YouTube app in Movie Mode :

For comparison, here is how it looks on my tv, with all the ghosting you'd want :

[Tiayeahdude]

My q80t does not have the bug, I tried both from xbox one x and from disney plus and netflix (TV bought in Italy in November 2020)

[BogaMoge]

Same thing happened to me... I mean, we had to expect that, right? A company that does not acknowledge any issues with its product, and can even get the point of lying to its customers... of course they won't allow bad reviews on their own site!

[Gustaverus]

I have a Q95T and only with static images I have the dimming bug after 6 minutes. Is it a general software problem or would replacing the device help?

[BogaMoge]

I wouldn't bet on a replacement making it better, I have been on these forums and others for 4 months now, and I haven't heard anyone that got this issue resolved by replacing their sets.

You may expect an update, but it's very touch and go, since some updates seem to make it go away for some but not all, and then another update brings it back, but not for all again.

My take : Samsung has dropped the ball with their Qled 2020, and they won't admit it, and most certainly won't really fix them.

[Suriya]

Very Poor local dimming on game-mode 

https://eu.community.samsung.com/t5/tv/q95t-v1461-0-terrible-local-dimming-on-game-mode/m-p/2511152#...

[Galaxy_Echo]

The issue (TV drops brightness in every 6 minutes) doesn't only happen in Game mode but also in EVERY modes. I suffer the same problem while playing PS5 in Natural and Standard mode, all ECO and intelligent options had been turned off.

My firmware is 1461, the latest version in Asia.

[peterQ95T]

Yesterday Samsung replaced my Q95T with a new panel due to deadpixels and Dimmingzone fault.

Everything was ok until i notice that the new panel have really bad DSE!😡😡. 

Im soooo tired of these Faulty TVs