Hi,
Just bought my sister the U2515H. I have one, and it is working like a charm. However, the one that I got her just isn't working.
We initially connected the monitor via HDMI to her desktop (win7 x64, i5) and it was working great with usb upstream cable and everything (installed the Dell drivers as well). Resolution was 2560x1440p. The desktop was left on and at some point went to sleep. After that the monitor just did not want to turn on. We tried changing the cable and used the mini DP one that was included with the monitor (without any adapters at the desktop side, just plugged it to the DP on the graphics card) and nothing happened. We tried unplugging the usb upstream cable, and still nothing. All the time the indicator led was blinking in the 5 seconds interval. We tried unplugging the power cable as well, and nothing. I mean the dell logo would appear and than it would just go black in a matter of a part of a second. Have no idea what to do.
Please help.