NUC recognizes as TVs, monitors with integrated speakers. Now, please tell me more about the issue. Usually as soon as you shutdown the NUC or enters into sleep mode the Monitor LED changes from Blue or Green to Red or Orange. Is LED of the monitor changing of color?
Please double check the power options of Windows® 7.
I’ll be waiting your answer.
The problem is that when either the NUC goes to sleep or when I configure the monitor to be turned off after x time, monitor stays powered on, i.e. (as you indicate), monitor does not go from full power (LED Blue) to standby (Orange power). This NUC replaced a current generation Mac Mini and it did operate under the correct behaviour as I would expect (using Mac OS).
I have check, changed sleep settings on windows 7 and confident they are set up correctly. The NUC is connected from the mini HDMI connection to the HDMI port of the ASUS monitor. I have looked at settings on the ASUS monitor (along with looking at manual) and see no special settings.
What ends up happening either with "Put computer to sleep" or having "Turn off the display". Display does go dark, then blue (fully powered on still) with message that "HDMI no connection" in box that floats around screen. I would expect monitor to sleep (LED goes from Blue (powered full-on) to LED goes to orange (powered-standby).
It seems to be an issue with your monitor settings. You are receiving a message in your display “HDMI no connection”; it means the NUC is turning off the video signal.
Monitors usually detect the lack of video input and get into standby mode. Do you have any other device connected to the monitor?
I'll agree with mike here. I have this exact model of monitor connected to a NUC5i7RYH (weird that I had the same monitor and NUC model connected to one another) and it goes to sleep just fine. I was initially running it with Windows 7 and have since upgraded to Windows 10. No issues. Windows should detect the monitor as an HDMI display and HDMI audio. That's normal. One thing I can suggest is trying another cable. I've seen issues with some hdmi to mini-hdmi cables. On some I wasn't able to get to full 1080p, others the display would randomly disconnect or not let the NUC boot. I even had one where every so often the screen would start shaking and I had to unplug and reconnect the cable to fix it. In all cases replacing the cable fixed the issue, so I would give a different cable a try if you can.