I have the same issue as threads posted here and here. Faint horizontal lines, mostly visible on light grey and white screens.
I have reset the monitor to factory settings, run the built in diagnostics (BID) and taken photos of the test screens. My iphone camera doesn't obviously pick up the issue though, so not much point in me sending them to you.
This has been tested with a Dell Latitude E7470 (Intel HD Graphics 520) on miniDP-miniDP and miniDP-DP cables and a Dell Inspiron 13 5000 Series (Intel HD Graphics 620) over HDMI. Both running Windows 10.
I've also tested with a MacBook Air 2011.
This is obviously a problem with the monitor, not the cables or laptops.
Do I go back via the store I purchased the monitor, or via Dell?
You should try to return it to the store for refund. We cannot refund it because you did not buy it from us. All we can do is setup a like for like exchange.
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