What causes a "trace" on the monitor?

Question

Iron

Good day. Monitor Dell U2312HM. Symptoms: in the right part to the full height - flickering, color distortion (into the purple area), once I observed the silhouette of a picture on a black background, which had been on the monitor for about an hour before.
I checked on different outputs (DVI, VGA), and on different computers - the symptoms did not disappear. Tell me what it could be, is there any hope, and how to fight so that this does not happen? Is it normal with current monitor matrices to keep the same picture on them for a long time?
Photo where you can see the departure to purple on the right - yadi.sk/d/R07pQCAdKjFLq. Capture the "silhouette" does not work.

Answer 1

if powering off the monitor does not help, then something has gone wrong with the matrix.

Answer 2

If you can, then throw off a photo of the monitor so that we can more accurately determine