Overclocking a dell u2414h help please

[ToastyX]

Higher refresh rates shouldn't cause that to happen. Either there's a driver bug, or the monitor is not handling HDCP properly at higher refresh rates. Maybe the monitor or GPU is having trouble with the reduced blanking needed to fit 75 Hz within 165 MHz pixel clock, but then the screen should get scrambled or black out.

If you used CRU at some point, run reset-all.exe and reboot to remove all the EDID overrides just in case that is triggering the problem.