Thin black lines flickering across monitor when scrolling

If it only happens in the browser, turn off hardware acceleration in the browser settings and see if the lines go. That one fixed it for me on a high refresh monitor.

Lines that only show up while scrolling are usually a cable or refresh rate problem, not a dying panel. Try these in order: - swap the cable, and try DisplayPort if you're on HDMI (or the other way round) - check Windows is actually running the monitor at its full refresh rate (Settings > Display > Advanced display) - turn overdrive / response time boost off in the monitor's own menu - update the GPU driver If the lines are still there over the monitor's own on-screen menu, it's the monitor itself.