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KWalt9
Beginner
1,725 Views

Screen flickering (black screen flashes) when using LG Utrafine 5K display as primary or extended display on my Windows 10 laptop (MacBook Pro) with Intel® Iris® Plus Graphics 650.

Hello,

 

My LG Ultrafine 5K second screen blinks (flickers black for 1-2 sec) when using internet browser (Edge, Chrome). Also when using MS Office applications (Excel, Powerpoint) but less often.

Switching the display to second screen only (=> turning of the laptop screen) makes it better but still some black screens and internet browsing is unusable due to the high rat of the bug.

This does not happen on MacOS so it’s not hardware-related.

 

I'm attaching bug report, Intel diagnostic tool, SSU, and a video of the issue.

 

hope you can help,

 

Thanks, regards,

 

Kev

0 Kudos
17 Replies
AlHill
Super User
1,577 Views

Apple has requested that all inquiries regarding their hardware be directed to Apple support.

 

Doc

 

KWalt9
Beginner
1,577 Views

Thanks Al, unfortunately that doesn't help. I've already reached out to Apple support with no luck.

 

As the screen is LG, the graphic card Intel and the OS Windows, I thought I might find a lead here.

 

What would usually cause black screen flickering on a high-resolution setup while Intel drivers are up to date and the screen/cable is not damaged?

AlHill
Super User
1,577 Views

"Thanks Al, unfortunately that doesn't help. I've already reached out to Apple support with no luck. "

 

I am just the messenger.

 

Doc

AndrewG_Intel
Moderator
1,577 Views

Hello KWalt9

 

Thank you for posting on the Intel® communities.

 

We would like to jump in and confirm that the information provided by Al.Hill is correct. Apple* has explicitly requested all support inquiries or issues be addressed directly to them and this applies also when using Intel® Graphics and supported Windows® Operating systems since the system is still running on an Apple* platform.

 

Thank you for your understanding.

 

Best regards,

 

Andrew G.

Intel Customer Support Technician

n_scott_pearson
Super User Retired Employee
1,577 Views

However (there's always a 'however'; it's like a 'but'), there are other, eerily similar reports that also need to be looked at, so this probably needs to be tracked here regardless of the issue going to Apple.

 

My two cents worth: this resolution, when running at 60Hz, is very close to, if not over, the transmission limits for DisplayPort 1.2 (see https://en.wikipedia.org/wiki/DisplayPort). The flashing screen is the symptom of the connection being lost and having to be reestablished. Switching to 30Hz should result in a reliable connection (please try that, if only as an experiment). It could also be the result of having a borderline cable. You could also try using a higher quality cable. [Aside: I don't know if it's the case here, but I will say it anyway: I have a rule: If the cable came with a monitor, it is CRAP and should be thrown away. Spend the money and get a replacement; avoid the pain this will undoubtedly cause.]

 

...S

KWalt9
Beginner
1,577 Views

Tanks Scott.

 

I have replaced the cable provided with the screen by an expensive and much shorter one.

 

From the intel configuration utility I can only change rate from 59 to 60 Hz, it will not accept lower frequency (and blinks also at 59Hz).

 

I've tried to screenshot the issue but recording the screen does not capture the blink (that's why I made a video with my phone) and it happens mostly with internet browsing or video playing.

 

Regards,

 

Kev

n_scott_pearson
Super User Retired Employee
1,577 Views

Hhmmm, I (still) have the Control Panel App installed and I can use it to lower it to 30Hz without issue. Not sure when they made that change in Command Center, but it's really idiotic.

Intel Customer Support: please provide feedback to graphics team regarding this.

 

Yes, this is a physical happening and not something you can record, so using your phone is the only thing you can do. As I said, the flashes are the TV and PC re-establishing communication.

 

I will have to think about this some more...

...S

AndrewG_Intel
Moderator
1,577 Views

Hello all

 

Thank you for posting on the Intel® communities.

 

Regarding the feedback about the option in the Intel® Graphics Command Center to adjust refresh rate, it is worth mentioning that the tool is designed and programmed to show only supported video modes (Resolution + Refresh rate) for each display. To investigate this further we would like you to provide us with a Report for Intel® Graphics Drivers to verify the EDID data of each Display involved. 

 

KWalt9 you may provide the report using the Intel® Graphics Command Center and n.scott.pearson you may use either only Intel® HD Graphics Control Panel or both if applicable. Thank you in advance.

 

Best regards,

 

Andrew G.

Intel Customer Support Technician

n_scott_pearson
Super User Retired Employee
1,577 Views

Andrew,

 

I was testing on a BN NUC with latest BIOS and drivers and a 4K TV connected to the USB-C port using a USB-C-to-HDMI adapter that supports 4K@60Hz and HDR.

 

Yesterday, within IGCC, I could only choose 59Hz or 60Hz. In IGCP, however, I could choose any frequency down to 23Hz.

Just now, when I checked it again. IGCC is now letting me pick any frequency down to 23Hz.

 

*I* didn't update anything (honest!) and the machine hasn't rebooted.

 

What I think happened is that, when I made a change in the frequency using IGCP yesterday, this allowed IGCC to then be able to do the same thing.

 

I will run some hard and soft power cycles and see if I can repeat this...

 

It's crap like this that gave me gray hair!

....S

n_scott_pearson
Super User Retired Employee
1,577 Views

Nope, I cannot reproduce.

n_scott_pearson
Super User Retired Employee
1,577 Views

Here are the two reports.

...S

AndrewG_Intel
Moderator
1,577 Views

Hello n.scott.pearson

 

Thank you very much for the reports and all the details.

 

We were also doing some tests regarding the behavior described and we could not reproduce it yet. However, we are still checking this. Could you please confirm the version of the Intel® Graphics Command Center? In the tool, please refer to Support >> System Diagnostic.

 

Also, we would like to know if KWalt9 was able to gather the report and feedback when trying to change the refresh rate and the Intel® Graphics Command Center version.

 

Best regards,

 

Andrew G.

Intel Customer Support Technician

KWalt9
Beginner
1,577 Views

Hi,

 

The report attached shows that only 60p is available for the LG Ultrafine :

 

Supported Modes:

640 x 480 (60p Hz)

2560 x 1440 (60p Hz)

3840 x 2160 (60p Hz)

 

But the utility allows me to choose 59p or 60p and offers higher resolution.

 

Regards,

 

Kevin

n_scott_pearson
Super User Retired Employee
1,577 Views

I have IGCC 1.100.2727.0. Seems like this is information that the app should include in the reports it generates...just saying.

...S

AndrewG_Intel
Moderator
1,577 Views

Hello all,

 

Thank you for the additional details provided and feedback.

We are still checking this behavior regarding Intel® Grapchis Command Center. As soon as we have more information available we will be updating this thread.

 

Best regards,

 

Andrew G.

Intel Customer Support Technician

AndrewG_Intel
Moderator
1,577 Views

Hello KWalt9,

 

We would like to update this thread and inform you that we are working on this case regarding the Intel® Graphics Command Center not showing refresh rates lower than the maximum supported by the Display.

 

In your particular scenario, since the logs are indicating that you are running Windows® on a Mac* system this investigation may take a longer time since this configuration is not readily available to us.

We will proceed to close this thread temporarily, however, you can contact Intel® Customer Support to follow up on the bug status (bug id CHJ-2432) in the future.

 

Thank you for your patience and understanding.

 

Best regards,

 

Andrew G.

Intel Customer Support Technician

Gal_Zk
Employee
1,266 Views

I have the exact same issue with my NUC7i7BNH connected to my Samsung 7 series TV. I bought newer HDMI cables with 60Hz support but it didn't fix it.

After hours of updating the bios/and driver to older and newer version, I finally found one (from 2018) which is pretty stable and flickering appears only while playing specific 4k 60Hz videos. 

The problem still exist but its much better (I configured the NUC to work on 60Hz).

The driver version I'm using is 24.20.100.6286.

Thx,

Gal.  

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