Monitor won't sleep properly. Goes black, indicator light is still on

Lol, Windows can be frustrating at times for sure. I figured with all of the users out there, someone else had the same problem and was able to figure it out the root cause. There is a root cause, just need to identify it.

lzj88 said:

Lol, Windows can be frustrating at times for sure. I figured with all of the users out there, someone else had the same problem and was able to figure it out the root cause. There is a root cause, just need to identify it.

If your BIOS and drivers are up to date, I can't think of anything else to check ATM. Others may have suggestions.

BIOS and drivers are all up to date.

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I have been experimenting with all sorts of software settings in BIOS and windows with no luck. I disconnected every single USB peripheral. I turned off every single background program I could find, also had no luck. What I did determine after swapping around hardware is the following:
-1 monitor connected via HDMI the monitor properly stays asleep
-1 monitor connected via DP the monitor properly stays asleep
-2 monitors connected, one via DP one via HDMI, the HDMI monitor sleeps properly the DP does not
-2 monitors connected, both via DP, neither monitor stays asleep

I have swapped out DP cables of different make/model, changed the DP version on the monitors software, tried different DP ports, but these all had no impact on my results.

Any ideas?

Thanks for the tip. Not sure which monitor this was referring to. My monitor has a DP 1.1 and DP 1.2 selector to choose the mode. I already tried both modes before and it had no effect unfortunately.

So today I had access to other monitors with a DP connector. I hooked up 2 other monitors (an NEC and a BenQ both of different size, age, and resolution) and 1 of my original Asus monitors and....only the Asus isn't sleeping properly. So mystery one solved, but now I have no idea why the Asus isn't working properly. Asus drivers installed or not installed makes no difference, and I don't see a BIOS update online for the Asus. I wonder why the Asus has this problem....hope I can figure it out as they are well past their return date. Any ideas?

lzj88 said:

So today I had access to other monitors with a DP connector. I hooked up 2 other monitors (an NEC and a BenQ both of different size, age, and resolution) and 1 of my original Asus monitors and....only the Asus isn't sleeping properly. So mystery one solved, but now I have no idea why the Asus isn't working properly. Asus drivers installed or not installed makes no difference, and I don't see a BIOS update online for the Asus. I wonder why the Asus has this problem....hope I can figure it out as they are well past their return date. Any ideas?

Did you try switching PC video output+cable between Asus and another monitor that does sleep?

After some back and forth with Asus CS which is still ongoing but not yet fruitful, I decided to try out a set of 3 DP to HDMI cables which...actually...fixed the problem. So, it's still a mystery why using the DP monitor input is causing this problem, but at least the problem is resolved by plugging in to the HDMI monitor inputs.

I guess I can mark this one as solved, but in reality it's not. I am sure other people out there have discovered this bug and Asus should be fixing it, but for now my battle is over. I am happy to have pay 45 bucks in cables to get this fixed.

To repeat and for reference, this only happens with 2 or more monitors connected via DP at once. 1 DP works fine, 1 DP and 1 or 2 HDMI works fine. Not sure of this problem plagues other ProArt monitors but it's clear to me DP is the culprit.

After trying different suggested on Internet combinations of monitor/windows settings with no success, I tried to switch monitor setting "Auto Source Detection" to "OFF" and manually select DisplayPort as input source.

This solve my issue with stable sleep mode of the monitor.