Hi, I've been redirected here to see if you can help:
I have a problem with my brand new U2414H screen and XPS13 9333 ultrabook running Win 8.1 (plus same issue running Win7).
Screen is connected with supplied miniDP cable, all drivers are up-to-date and the ultrabook screen is fine.
When I power the XPS up and it switches to the external monitor the screen displays random flickering horizontal blocks of white/noise, if I just press the monitor's power button off and on the screen is perfectly fine from that point on.
If I restart the laptop/it goes to sleep/shutdown and then switch on again then the flickering/noise problem returns.
Any ideas?
Full thread and thoughts from Dell are here: http://en.community.dell.com/support-forums/peripherals/f/3529/t/19540049.aspx