Dell Monitor shows weird discoloration that is spreading; it is not a physical stain from outside.

[kdentals]

My Dell U2311H monitor seems to have developed a weird beige-light brown discoloration/ stain that is spreading across the screen.
I have used this monitor for at least 5 years. This is definitely not a stain from being touched or cleaned or a spill. I last cleaned it about 7 months ago and was very gentle and used a feather duster and there were absolutely no problems for months.
This stain is not visible when monitor is off. I believe it is something to do with inside the monitor.
There has been no spill at the back of the monitor either. I have no reason to believe any water got inside or fungus is growing on the back side of the screen.
What can I do? When I had a CRT I could at least try degauzzing it. If there was a problem displaying something on windows explorer I could refresh it. But with this weird discolouration, does it mean my monitor should be retired?

 

[Lakken]

I do think is just getting old. the hardware behind the glass are too worn out.

 

[kdentals]

Can you give a more complete reply? Anyone can just say something is getting old. There are many old monitors that don't show this problem, and I have never come across this before.

 

[Lakken]

I had similar problem on one of my old monitors. on mine it was on the right side of the screen. I had warranty still on it, so I could send it back to the place I bought it. They fixed it. I dont know how, unforntunately.

But when happend again, I had no warranty and just got a newer, bigger one...😛