Possible solution to Dell S2309W stuck in "Power Saving Mode"
I just hooked up my new Dell S2309W monitor to a ten year old G4 Mac with the original video card using the Dell DVI cable that came with the monitor.
Initially everything went fine - auto-detect on the Dell worked and it selected the DVI input, the Mac recognized the Dell model and set the resolution to 1920 x 1080.
Everything seemed to be A OK but only for about five minutes.
Then the monitor turned off by itself telling me it was in "Power Saving Mode" and to hit any key on the keyboard or move the mouse to turn it back on, but nothing worked.
I disconnected the DVI cable, disconnected the power cable, rebooted the Mac, but the monitor was "stuck" in power saver mode.
So I eventually hooked up the monitor with the VGA cable (which worked) and did some googling - turns out there is quite a bit of info on the net about this problem with Dell monitors, not just this specific model.
In most cases either no solution or suggestion to replace the monitor and/or the video card; one person suggested changing the DVI cable.
That's exactly what I tried next - used a better DVI cable I had already, and so far so good - monitor has been on steady for about an hour now and everything is working.
Just a note in case someone else on ehMac has that problem with that monitor or any other Dell monitor.