Hi,
My Dell U2312HM is having some problems. It is noticeable in normal usage as a discolouration towards the right hand side of the screen, as well as pixellation, manifesting in dark horizontal lines.
I've run the self test by holding down button 1 & 4, and it is most noticeable on the grey test, in which there is a gradient of colour from the left to right. The right hand side has a significant blue/green tinge as shown in this image - http://imgur.com/a/lvviV (images of other tests included). These tests were carried out without the DVI cable inserted, but the results are the same regardless. I should also point out that the camera doesn't quite capture the full extent of this. This had previously happened with the monitor several weeks ago, but resolved itself after being unplugged for approx 12 hours. I did not have the same luck this time around, unfortunately.
If I could be given information on troubleshooting this issue, or if necessary, the steps I need to take in order to have the monitor replaced, I would be very grateful.