Dark corners, Q9 local dimming issue

[userezv49wXuc2]

Hi,

I've seen discussions on local dimming and how it affects image quality. I've been experiencing issues relating to this as well, specifically darkness predominantly around the four corners. This only occurs when there are black bars at the top and bottom of the screen i.e. when watching movies. It doesn't happen all the time, for example it doesn't occur watching some shows on Netflix when the black bars are very thin but it will happen when the black bars are thicker.

I tried adjusting the picture settings which didn't help. However I did enter the service menu and increased the pwm settings to 100, which alleviates the issue but doesn't resolve it completely. I also tried setting local dimming to 0 through the service menu, which resolves the issue but introduces another issue in that the screen flickers, as though the frame rate drops to about 20~fps.

This seems to be a software issue, as pressing pause to raise the pause widget or bring up the tv settings makes the darkness go away completely while the widget is visible. The darkness returns gradually after a few seconds when the widgets go away.

Does anyone have a way to resolve the screen flicker after turning local dimming? That would be the ideal solution. Actually the ideal solution would be a firmware update with an official solution.

My TV is the 88" Q9 QLED. Here's an example of the problem:

I've uploaded a video of the issue as well. Notice that the problem gradually occurs over a few seconds. Likewise, when the black bars go away the problem gradually fades away.

https://www.youtube.com/watch?v=rL_EAqfv-JU

[userIKcIVfT6hx]

I get this on my 75 inch Q90r. It's really quite frustrating. There is also no pattern 90% of the time it works fine. I would love to here an official Samsung response. I will drop a pic in a bit.

[userIKcIVfT6hx]

Dimming problem 

Here's a small video of what I see.. You can see the bars creep into the video here. I turned the pic to black and white to make it more visible.

[SamsungLarry]

Does this occur on all sources?

[userIKcIVfT6hx]

If you are referring to confused dimming on the Q90r 75 inch in the vid clips linked to above then yes it applies to all sources. I can't speak for @userezv49wXuc2. 

[userezv49wXuc2]

Yes, this occurs on all sources. 

[SamsungLarry · Accepted solution]

I recommend letting a service technician have a look. Send your full model code and serial number via private message to get started.

[userezv49wXuc2]

Can we remove the "solved" status? The problem hasn't been looked at by a technician yet, so it remains unsolved.