The screen is getting darker and the colors are less saturated, what's the problem?

Question

Monitors

Recently noticed such a problem, the screen became darker and less saturated. The colors are somehow faded, not much, but you can see the difference, I noticed that this happens when the PC is turned on for a very long time, and sometimes just when I turn on the PC, it is immediately clear that the screen is not bright enough, as if in economy mode.
The problem is solved if you open the monitor, pull out all the cables and put it back, at least once it helped. That is, the screen is not always darkish, when it is noticeable. What could be the problem?
Could there be a problem in w10? What services, etc. I
reinstalled firewood, it's no use .. Maybe the block from the monitor does not give enough power, in general I don't know;)
LG FLATRON E2442 5-6 years of operation

Answer 1

Check the socket and cable, try another wire.
Often this is the problem.