I have a few days ago received this monitor.
Samsung S23A750D 23" 120Hz
I am using it with a Gainward Nvidia GTX570 Phantom GPU via DisplayPort cabling.
The trouble I am having is that the monitor has great trouble picking up a signal from the GPU when the computer has gone into sleep mode or been switched off (at this point I can get a signal to the monitor). It's only when I turn the computer back on and then the monitor that I get no signal. To get a signal I have to remove the power cable and put back in or sometimes remove the DP cable and put back in.
I have tried not turning the monitor off (the monitor goes into a sleep mode when the computer goes into sleep mode) but on putting the computer on it does not pick up a signal.
It is only by removing the power cable and/or DisplayPort cable will I get a signal. And this is intermittent.
I have tried upgrading the firmware from Samsung but this hasn't helped.