Goodness man, you really did not need to post this almost 10 times, once was more than enough, I've left this and removed the others.

While the hotkey to blank the monitor would initially work, I do not believe that you can do what you want with this model line, unless someone else has a suggestion I suspect the final answer may be "not possible here"

This isn't a "problem" since they were never meant to work the way that you want them to work, there is no physical way to cut power to the monitor, it assumes that if you're working on it, you're in front of it.

Besides, if you remote to it via RDP the screen displays locked, other software responds in different ways. This really is a very uncommon request and I suspect it can't be resolved the way you want.

RDP is unique, and I'd recommend it, however some of the logmein programs do allow screen blanking, but you would have to dig more in to them since I don't use them at this time.

If you goal is to not wake a sleeping person in the room when you remote in, then there isn't a solution, if the goal is to not let the person in the room see what you're doing that might work with a logmein option, but once again, this is not a common request.