2020 QLED T models (Q80T, Q90T, Q800T, Q900T) HDR game mode brightness / local dimming bug - Page 182

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

Duner · ‎08-12-2020

New firmware UP for Q95T on EU support!

ver 1460.9
1602.86 MB
Dec 08. 2020

anyone has patch info?

gonna flash it now, will test all night and post here

Toejo78 · ‎08-12-2020

Yeah it's a disaster

Rauttis · ‎08-12-2020

I only have the Q80T, but even then this is the most expensive TV I've bought so far, and yet it'll probably be the one that will have the shortest lifespan for me. I'll probably get a new TV when the 2021 models come out, probably LG oled.

I only now tested 120hz for the first time, and man, now I can see what people have been complaining about regarding inverse ghosting. This is the worst case I've seen on any display I've ever owned: https://www.youtube.com/watch?v=LGr6a4jiZEg

Don't buy these TVs for gaming, just don't. For watching movies they are ok.

cragcrag · ‎08-12-2020

So what is it we're looking at here? The sort of "halo" effect where the colour is normal in the middle,and all around it's whiter/faded?

Rauttis · ‎08-12-2020

Inverse ghosting is the bright green / purple highlights around objects when moving the camera. It's most obvious around the ropes in the beginning of the video. The "halo" effect is more a side effect of the camera being close to the tv (and the bad local dimming performance in game mode), it doesn't look that bad in person. The inverse ghosting however looks just as bad if not worse in person, since the green color looks even brighter than it does on camera here.

BogaMoge · ‎08-12-2020

New firmware update (T-NKMDEUC-1460.9 for EU).

First test : Local Dimming in Game mode

Movie Mode HDR (Local Dimming on High) :

Game Mode HDR (Local Dimming on High) :

Game Mode HDR (Local Dimming on Low) :

Conclusion : No apparent changes from Firmware 1403.1, local dimming is still bad in Game Mode.

Second test : Purple Ghosting in Movie Mode while gaming
Firmware 1460.9 :

And for comparison, this was Firmware 1402.6 (there was no difference on that point between 1402.6 and 1403.1) :

So they definitely did something but :

the purple ghosting is far from gone
when I tried this in AC Origins, which had very bad purple ghosting for me before, it was now transformed in the light green ghosting some users have been documenting on this thread. Needs more checks...

My guess is that they are trying to find a balance between normal and inverse ghosting, but are just getting messier and messier each time... Give us the simple ability to set the pixel response time ourselves dammit, how can it be so hard?!
Conclusion : minor changes, but need more testing to verify if more issues arised than were solved (since really none of them were).

Third test : Scanlines in Game Mode

I'm unable to provide any capture (I've tried, but it never came up ok, using a simple phone will have its limit I guess) but scanlines are still there. Needs a lot more testing to evaluate if they're less noticeable, but since they shouldn't be even just slightly noticeable, it doesn't really matter.

GENERAL CONCLUSION :

No issue (of mine at least) has been resolved with this last update. It is absolutely unacceptable that I (like a growing number of usrs) experience these issue after 6 months of owning this tv, 5 different firmwares and having the screen and motherboard replaced.

My personal situation makes it hard for me to repack the tv (and then maybe unpack a new one), but I'm really beyond frustrated right now...

portuguese83 · ‎09-12-2020

Tech came today and replaced panel and motherboard....still have purple ghosting, not as bad as b4 but still is noticable. How much money is Samsung gonna loose b4 they actually admit that this is a problem

BogaMoge · ‎10-12-2020

I'm not surprised. My tv came back after getting its screen and motherboard replaced too, but the issues continue even with firmware 1460.9.

What did the tech say when you tested the tv after the part swap? What are you going to do, going for a refund?

Tiayeahdude · ‎10-12-2020

Stesso problema anche in Italia per me ghosting su ogni gioco xbox one x e colori non reali

Superdooper · ‎11-12-2020

I did the update last night hoping it would resolve the dimming problem of HDR content after 6mins. But guess what still no fix, tv still dims after 6mins.