Connecting a Dell U2412M to a 2013 Retina MacBook Pro using DisplayPort to Mini DisplayPort I recently got a Dell U2412M monitor. I'm attempting to connect it to my 2013 Retina MacBook Pro using a DisplayPort to Mini DisplayPort cable. I repeatedly get a "Entering Power Saving Mode" dialog on the monitor. The only time I've been able to successfully connect to the monitor is if I unplug the monitor completely, turn off the computer and turn them on in sync (even this only works 30% of the time). However, connecting it using a Mini DisplayPort to VGA adapter works as expected.

Is there a way to force the computer to detect the display using the terminal? I've tried using apps from the App Store that bring back the old Detect Displays option, but those don't work either. 

There are posts regarding this on other sites, but none provide a solution. Since the DisplayPort to Mini DisplayPort cable are the most convenient to use, so I wanted to see if anyone here has solved a similar issue, before giving up and using DVI.
I had the exact same problem with a Dell monitor.  After months of support calls and monitor replacements, it ended up being the cable.

The problem was using a Mini-DP to DP cable.  For some reason, the DP chips in the cable is not sending a signal that Dell monitors are expecting or the length of the cable causes the signal to degrade.

The fix? Buy a Mini-DP to DP adapter then use a 1.2 DP to DP cable to connect to the monitor.  I know it sounds lame and the MiniDP to DP cable should work but after I switched out the cable for this setup, I didn't experience the issue again.

Hope this helps.