Re: 2020 QLED T models (Q80T, Q90T, Q800T, Q900T) HDR game mode brightness / local dimming bug - Page 186

Rauttis · ‎10-05-2020

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:

Set brightness to max (50)
Set local dimming to standard (bug happens on high as well)
Enable game mode
Turn off game motion plus
Turn off intelligent mode and all the brightness related settings in eco settings, as these can influence the brightness level of the tv.
Launch a game that runs in HDR
Start your stopwatch
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
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.
Go to picture settings and set local dimming to low (brightness does not change)
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)
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

daparky · ‎17-12-2020

*****, sorry to hear that. It sounds like you're stuck with Samsung then?

Sell it privately?

BogaMoge · ‎17-12-2020

@daparky wrote:

*****, sorry to hear that. It sounds like you're stuck with Samsung then?

Sell it privately?

That would be a *****ty move for me to sell a defective product to someone else...

Right now, I'm using all pressure points possible to Samsung and my retailer... but I don't have much hope. They don't care about lying and being incoherent, so hard to talk to someone who answers that way.

The next step will be mediation companies (that's what we have here in Belgium).

And if that still doesn't work, there is only legal options...

What an absolute mess this tv and this situation have been!

PeterHu · ‎20-12-2020

I might have found a temporary solution or workaround for the local dimming and subtitle bug on 1460.9 Firmware:

I played with all the settings, and if you keep the local dimming on low (where it drops to if it's on standard or high), then with contrast enchancer on low or high - depends on your liking - compensates the lack of brightness. It depends on the content too which local dimming settings are the best.

I am using Rtings settings by the way.

And other important I just noticed:

Picture Mode settings vary on SDR and HDR!

So if you set up everyrhing correrctly with a normal Youtube video for example in Movie Mode, if you play HDR content (same Youtube or Netflix Premium or external HDD and Pocture Settings icon contains the HDR logo) then the settings are different in the same Movie Mode. I did not try with HDR10+ content but I wouldn't be surprised if it would be separated too.

BogaMoge · ‎20-12-2020

Well, I have been using Local Dimming Low and Contrast Enhancer Low since the local dimming became non functional on Game Mode, but as you said : lower brightness, oversaturated whites because of CE, and the bad local dimming is still very noticeable in dark scenes so I would not consider it a "workaround", even temporary. It is, at best, customers having to settle with subpar performance from their premium product because Samsung can't be bothered to fix their tvs.

And of course picture settings are going to vary between SDR and HDR, these are two vastly different way of managing picture, so the settings don't have the same effect in SDR and HDR. You can also choose to apply picture settings to all sources or current sources, which I normally do to get my preferred settings for every source (since only 5+1 picture modes, with 2 of them unusable (Dynamic and Natural) is really not enough if you want a good display for all kind of content).

daparky · ‎21-12-2020

Got my XH95, recorded a couple of videos playing COD upscaled 4k at 120fps. No ghosting or scan lines in sigh, no dimming bug, no dse. This is how it should be done.

https://youtu.be/2fIob3_qMmE

https://youtu.be/sDI_aRypi_A

Suriya · ‎23-12-2020

Created a petition for game-mode issues

https://eu.community.samsung.com/t5/tv/petition-need-game-mode1-and-game-mode2-q95t-q90t-q80t-q85t/t...

lmpcardoso · ‎23-12-2020

Hi! The local dimming it’s not the only problem. There are other problems, and problems that I think it’s worse than this. For example inversion of colours, ghosting, judder on low frame rate content, scanlines on 120hz mode ( I even have scanlines at 60hz on my Q80T), DSE.
They need to start from one point but they must be aware that local dimming is not the only problem. They are selling premium TVs with a lots problems. That’s not expected wen you buy such product of this price range.
Samsung already lost me because I will not buy no more TVs from them.
Thank you all merry Christmas!!!

redlum77 · ‎23-12-2020

@PeterHu

What did the technician said about the DSE problem and did he change the panel? I also bought mine from Vandenborre but return it because of DSE (I didn't want to mess with tv replacement again and again...). But it's good to know if they akwnowleged the problem and corrected the issue.

PeterHu · ‎23-12-2020

He accepted the DSE and I have paper of it, and now I'll try to contact the Customer Service as he said he can't do anything about it. Christmas Holiday season doesn't help. And now, I checked in other stores too, same model and size, selected Youtube test videos in store...and had less DSE, great.

I sent pictures them too.

As I'm over the two weeks, I hope they still can change it, I'll use all my rights as the pruduct seems defect.

brook1 · ‎23-12-2020

Why did they create a forum in the first place if not for monitoring and fixing issues ? do they think we are chatting in here and having fun why don't the management itself take a look at THEIR OWN forum and start collecting information and release a statement regarding the issues and the fix patch date. It's really my last time buying Samsung product I will never do this to myself again even if they fix everything i just can't trust them anymore it's sad that i went all in to buy a q90t and it's my first time to buy a premium tv i had high expectations