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S2721QS, 4K HDMI not working?

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Hi,

I just purchased the S2721QS monitor from a Dell exclusive store in Greece (REV A01 - July 2020). 

I hooked it up using HDMI cable PROVIDED BY DELL with my laptop which has HDMI 2.0b and supports 5k@60hz output and I noticed that although 1920x1080@60Hz and 2560x1440@60Hz work fine, when I try to display 4K@60Hz the screen goes wild (although still recognizable) with very heavy horizontal flickering.

I believe that the HDMI cable provided by Dell is in fact HDMI v1.4 (Hotron 20276 E246588) and thus does not support 4k@60Hz. I cannot seem to find the spec sheet of that particular cable, but I did find a reference saying its 1.4.

Is there any chance I have damaged the monitor by forcing it to display 4k@60Hz with a bandwidth incompetent cable? I tried adjusting many settings via AMDs software and windows 10 settings before realizing that the cable must be at fault and it took a good ~30 minutes of intermittent flickering (I was going back to FHD changing some stuff, then back at 4k, etc.) - [Truth is I would have blamed the cable way earlier, but the fact that it worked on lower resolutions and the fact that it supported 4:2:0 subsampling (which HDMI v1.4 doesn't) confused me. Turns out AMDs drivers can make HDMI v.1.4 work with 4:2:0...]

I must say this has been a very disappointing experience for my first day of use. I honestly cannot understand how DELL decided it's appropriate to use a sub-optimal cable, without even warning the consumers that its not gonna work at the monitor's advertised resolution. Do bear in mind that the monitor does NOT support 24-30Hz, so an HDMI v.1.4 is completely incompetent of delivering 4K here.

I have not yet resolved the issue as I have no other HDMI 2.0 cables available right now, so I will update you tomorrow, but I am pretty sure that is the problem.

Regards,

Andreas

PS. While attempting to resolve the issue I installed the "DELL_S2721QS-MONITOR_A00-00_DRVR_KTRRG.exe" from the official Dell website. I, however, believe I messed up and actually downgraded my monitor (seeing as its A01). I suppose there's no way to revert that? I must wait patiently for the next file to be uploaded? Can anyone help me with that?

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Re: S2721QS, 4K HDMI not working?

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Update 18/10/20: Seeing as i cannot edit my posts, i would first of all like to publicly APOLOGIZE to DELL for blaming them and the monitor (S2721QS). Turns out the problem was software related and it had to do with lenovo and amd. My configuration: Lenovo yoga (ideapad for US market) slim 7 14ARE05 laptop AMD ryzen 7 4700U CPU with integrated AMD Radeon rx vega 7 graphics Windows 10 home (for version see bellow) Connection performed via HDMI to HDMI cable (provided by DELL) via the laptops built in HDMI port which is v2.0b Issue description: Connecting the laptop to the S2721QS at anything above 1920x1080@60Hz, ie 2560x1440@60Hz and 3840x2160@60Hz caused the monitor to show heavy horizontal flickering. Additionally the same flickering was also evident in the laptops built in display although at a less noticeable degree, hardly visible by the human eye. Both flickers were in sync at all times even when extending (not duplicating) displays and using different Hz options. Actions undertaken: I started by updating any driver software i could, starting with amd's adrenalin drivers for my 4700u via amd's official webpage. I then updated the monitor using the "DELL_S2721QS-MONITOR_A00-00_DRVR_KTRRG.exe", which is infact -as Chis correctly spotted- not a firmware update (which was showing M2B102 before and after installing) but rather an ICC profile along with some other stuff, which i dont really know what they are used for. My issue was not resolved so i proceeded to download and update the built in display and VGA drivers via lenovos webpage. Still the issue persisted, so i downloaded a new BIOS version, again via lenovos webpage. Finally i downloaded the windows 2004 version via windows update. Up until this point nothing showed any sign of working (issue was exactly the same, not better or worse). ISSUE RESOLUTION: The issue was finally resolved when i found out that others had the same problem with that particular laptop in the amd configuration only (and not with intel CPUs) and with various external monitors (dell, samsung, asus, etc.). Turns out i had to DDU all the amd drivers and clean install the lenovo modified (via lenovo vantage app) amd driver version which was the one installed on the laptop BEFORE i began this lengthy process described above. The issue instantly disappeared and both screens work perfectly now in all settings. Conclusion: Both the windows 2004 version and lenovos modified amd drivers are required. Seeing that my first step was to update the amd drivers via amd's webpage rendered all my other actions useless. Residual issues: There seems to be no way to install amd's radeon FULL adrenalin software, because lenovo only releases the driver version with the "radeon settings LITE". This is of course not dells problem. I also have another issue with the 8 vs 10-bit color; i cannot make the monitor display 10 bits even though i can enable the option; the monitor turns off completely (at all resolutions and Hz-so it's not a bandwidth issue). I will make a separate post, because i feel like this one is getting very hard to follow. Thanks Chris for taking the time to reply and I apologize once again for calling DELL out on this exceptional monitor. Regards, Andreas_P

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Re: S2721QS, 4K HDMI not working?

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Update 10/17/20:

I purchased the DeLock 84771 HDMI cable that supports 4K@60Hz.

The problem persists (even if i try to reduce the bandwidth required by using 4:2:0 subsampling with 8-bit color) as I cannot get rid of the horizontal flicker at 4K@60Hz. Additionally using high resolution video from my DSLR camera the flicker also seems to exist (although on a significantly less noticeable degree) at 1440p, so my initial blame on the HDMI cable provided by Dell was completely wrong. 

I will be contacting Dell service on monday to return the monitor and get a full refund.

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Re: S2721QS, 4K HDMI not working?

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To what PC model is the S2721QS attached?
What GPU video card is in the PC?
What operating system is on the PC?

Driver KTRRG is only 349.95 KB. I doubt that it is "firmware update". When you ran it, did it provide the Windows operating system S2721QS INF, CAT, ICM files? When run, did you see any mention of "updating firmware" ?


The provided FVY5J HDMI to HDMI cable is 2.0 matching both of the HDMI 2.0 ports.


Capture.JPG

 



 

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Re: S2721QS, 4K HDMI not working?

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Update 18/10/20: Seeing as i cannot edit my posts, i would first of all like to publicly APOLOGIZE to DELL for blaming them and the monitor (S2721QS). Turns out the problem was software related and it had to do with lenovo and amd. My configuration: Lenovo yoga (ideapad for US market) slim 7 14ARE05 laptop AMD ryzen 7 4700U CPU with integrated AMD Radeon rx vega 7 graphics Windows 10 home (for version see bellow) Connection performed via HDMI to HDMI cable (provided by DELL) via the laptops built in HDMI port which is v2.0b Issue description: Connecting the laptop to the S2721QS at anything above 1920x1080@60Hz, ie 2560x1440@60Hz and 3840x2160@60Hz caused the monitor to show heavy horizontal flickering. Additionally the same flickering was also evident in the laptops built in display although at a less noticeable degree, hardly visible by the human eye. Both flickers were in sync at all times even when extending (not duplicating) displays and using different Hz options. Actions undertaken: I started by updating any driver software i could, starting with amd's adrenalin drivers for my 4700u via amd's official webpage. I then updated the monitor using the "DELL_S2721QS-MONITOR_A00-00_DRVR_KTRRG.exe", which is infact -as Chis correctly spotted- not a firmware update (which was showing M2B102 before and after installing) but rather an ICC profile along with some other stuff, which i dont really know what they are used for. My issue was not resolved so i proceeded to download and update the built in display and VGA drivers via lenovos webpage. Still the issue persisted, so i downloaded a new BIOS version, again via lenovos webpage. Finally i downloaded the windows 2004 version via windows update. Up until this point nothing showed any sign of working (issue was exactly the same, not better or worse). ISSUE RESOLUTION: The issue was finally resolved when i found out that others had the same problem with that particular laptop in the amd configuration only (and not with intel CPUs) and with various external monitors (dell, samsung, asus, etc.). Turns out i had to DDU all the amd drivers and clean install the lenovo modified (via lenovo vantage app) amd driver version which was the one installed on the laptop BEFORE i began this lengthy process described above. The issue instantly disappeared and both screens work perfectly now in all settings. Conclusion: Both the windows 2004 version and lenovos modified amd drivers are required. Seeing that my first step was to update the amd drivers via amd's webpage rendered all my other actions useless. Residual issues: There seems to be no way to install amd's radeon FULL adrenalin software, because lenovo only releases the driver version with the "radeon settings LITE". This is of course not dells problem. I also have another issue with the 8 vs 10-bit color; i cannot make the monitor display 10 bits even though i can enable the option; the monitor turns off completely (at all resolutions and Hz-so it's not a bandwidth issue). I will make a separate post, because i feel like this one is getting very hard to follow. Thanks Chris for taking the time to reply and I apologize once again for calling DELL out on this exceptional monitor. Regards, Andreas_P

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