Hi - sounds like a related problem.   I just got 3 U2417H monitors.   Am running off of a 4 month old MSI GeForce 970 4GB video card with full size displayport .   The monitors are all on but they all blink on and off intermittently.  Usually 1-4 seconds one will go black and then back on.   Tried switching out the Dell supplied cables with brand new cables - same results.

Any help?