I have had an intermittent problem over the last week or so. Every now and then, a darker grey vertical stripe appears on my screen. Normally, this covers the left quarter of my screen, but sometimes covers the whole left half of the screen. It's almost as if I have reduced the brightness of only this part of the screen compared with the rest.
It has again just appeared without warning. I attach a photo of it below. I'm not sure if it's relevant, but this stripe does not appear in the image if I take a screen grab.
I am based in Liberia and not near a Dell service agent, as far as I am aware, until returning to the UK for Christmas, so having it looked at by a Dell agent is not a practical proposition for the time being.
Any ideas on what causes this and how I can resolve it?