I'm having problems getting my U2415 working with DP or mDP. After receiving it, it appeared to work just fine on DP connected to my Mac Mini. After a week, the screen went blank, said it's going into power saving mode. After some playing around, resetting, running the self test (passed) and making sure it worked with HDMI, things worked again with DP.

Over the next three weeks, as screen problems increased (blank screen, telling me there is no signal and going into power saving mode), I ended up trying another DP cable I bought (thinking the Dell cable was defective) and then a newly purchased mDP cable. Now it's at the point where I never can get the screen to work, unless I use HDMI (which is what I'm forced to now). I also checked with another computer, to make sure it's not the DP port on the Mac Mini, but I get the exact same issue.

I just passed the 30 day mark a week ago, so I'm curious of others are having this issue with the Rev 02 version of the U2415.