Add-On Monitor Not Sleeping

I have a nice new Asus Zenbook UX305UA which is working well with Windows 10. On my desk at home I have an Acer K222HQL monitor attached and the laptop.

In Windows I have set the Screen Off time to 20 minutes. If the laptop has no monitor attached this screen off time works perfectly. If the laptop stays with lid open and monitor attached then both screens work and both switch off after 20 minutes. When the monitor is attached, and the laptop lid is closed, then the attached monitor does not switch off.

That was all done with the Window+P panel set to Duplicate. So I changed that to Second Screen Only. It did not switch off.

My preference is to have the laptop lid closed and the attached monitor switching off. Is there something in the laptop settings that will cater for this?

 

The screen off now works. Don't know why. All that I have changed this morning is to use Wondows+P to change to Second Screen Only and then Windows+P to change back again to Duplicate screens.

Now I am happy - but it would be nice to know why.

 

My happiness was short-lived. After just 24 hours with the attached monitor switching off as desired it just stopped doing so. No reason, no changes, just stopped.
Looks like I am back to blaming Windows 10. A brief web search suggests I am far from alone.

 

Try updating the Intel HD graphics driver see if it helps.

 

Thanks. Worth a try but it came up with: "Error This computer does not meet the minimum requirements for installing the software". The install screen opened and files were extracted from the downloaded .exe and then this message. This machine should be well above any minimum requirements. It is Asus Zenbook UX305UA.

 

Which one did you use?
Try to remove the driver first, then reinstall again.

 

I went to the Intel website to download the latest driver. That site says it is Version: 15.33.38.64.4252 (Latest) Date: 7/29/2015
I looked up data on this laptop and find my graphics driver to be version 20.19.15.4331 Date 11/18/2015 which suggests it is newer.
Removing and replacing is a bit beyond my skills but if you still think it is worth a try I will go to my supplier and their tech can do it.

 

Please try this driver package instead (dated Dec 22, 2015).
[ Download]

 

Did that. No visible change. Tried it on just the attached monitor - not switching off.
It was nice when it worked. I was enjoying leaving it to look after itself and then the quick return to just where I was.

 

The sleep and screen closing software worked on my previous laptop with a Windows 10 upgrade, and this same monitor attached, and worked for a while on this machine which, I believe was built for Windows 10, with monitor attached.
So, I have done further tests and the results are (all for the laptop plugged to the power, not on battery) that when the laptop has no monitor attached then the screen switches off as required. When the laptop lid stays open and the monitor is attached then both switch off as required. When the laptop lid is closed the attached monitor stays switched on.
My settings for lid closing in the laptop when plugged in is "do nothing" (which does actually switch the screen off as the lid closes) otherwise the lid closing options are "Sleep, Hibernate, Shut Down" which I do not want.
This looks like when the laptop screen is off the laptop does nothing about the screen switching off instructions.
Is there another switch I have not found?

 

It's really hard to say but the issue could be any of the software issues such as BIOS, or driver, or Operating Systems.
Without actually looking into the issue myself I can't be sure which one, but based on the basic of troubleshooting steps I would do a clean install of Win10, then go from there.

If you encounter any issues during reinstall, feel free to let me know and I will try to help you out.