I have three 23" U2312HM monitors, one of which has begun to fail.
The right side of the screen is noticeably flickering, off color, with visible horizontal lines. I have run the diagnostic self tests and it is most prominent on the grey screen, however the issue is visible on all the others also. I ran the factory reset and then re ran the self test and the issues persisted. I proceeded to run the same tests on my other two monitors and both are totally fine.
I went to the support site but I gather monitors under 24" in size don't have service tags. I have the serial number and the date of manufacturer which are printed on the back. Is there any way I can get in touch with technical support and get this issue resolved? My understanding is monitors come with a three year warranty from the date of production, to that end mine should still be covered for another year.