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

[Suriya]

Are you with q80t? it seems now the local dimming in game-mode is full effective like previously it was on my q95t.

[QuantumP]

HQboy haven’t you got better things to do like following Suriya around praising him? Or donating money to that fraud.

[QuantumP]

Q95T here with Xbox One X and vrr enabled. No dimming issues. Looks amazing and brilliant.

[HQboy]

So stop, okay? Looks like you're faking this situation with him. And the strangest thing is that both are new users. This situation has already pissed off. Everyone uses the TV as they please, it is not the focus here. Are you @ AV2020 fakes? It can only be this.

[QuantumP]

HGIG is a nice touch on this tv. 

[AV2020]

You are weird. You speak broken English and have a weird way of words. 

[Suriya]

Yes that prematurely born @QuantumP is making multiple fake accounts to like his own posts and spamming with random user names. He is the best troll ever. Just ignore that premature poor born kid and focus on game-mode discussion

[MJ1931]

Answering a question about "do I use the calibration tool" only polite to answer, who are you the boss or summat

[Danmay]

For those of you still interested in the faults of this screen rather than calibration settings (which are obviously down to personal preference, so it's not worth arguing over), I have decided to initiate a return on my UK 55q90t.

If the screen worked as I had expected, with freesync without any issues I would've been over the moon.

I'm not sure why some of you don't have this issue, but VRR/freesync is very dark, and the colours are all over the place. Hardly gives you confidence that this will be a great screen for VRR in next gen.

The straw that broke the camel's back for me though are the faint scrolling lines without GMP on (even with both values set to 0). This is very odd behaviour for a TV and I have never seen it before. As I've said before, these are visible even with freesync/VRR.

Additionally, the Samsung seems to apply different overdrive to the pixels with GMP on/off. With GMP on, smearing and blur is fairly low, not as good as my old Sony but fine. With GMP off...well, the motion/smearing is quite a bit worse, and defeats the point of a 4k screen when in motion.

I'm aware no TV is perfect, and some of you don't have/haven't seen any of these issues, so that's great for you. The issue is, by various testing I think these issues are software issues. But I have no confidence these will be fixed, and the bizarre behaviour of GMP confuses me. I'm sure these screens will be much more polished in next year's range once 'next gen' is actually here.

[AV2020]

You are the fake. There is a YouTube video about you and your fraud act. It is funny to watch. You got exposed and lost any respect you had on here. 🤣