Problems with U2412M (buttons, lines, color fields)

I am using a U2412M display and it has begun having a variety of issues since yesterday.

• The capacitive and the physical on/off button do not function. The on/off icon remains lit blue even when the DVI cable is unattached.
• When I came in yesterday morning, the display had a black and blue checkerboard pattern instead of what I usually see (the Windows 7 login screen). This morning, it was a dark green field. I have also seen it change to a baby blue field while I was working.
• Today it has begun displaying vertical pink lines that vibrate throughout the display. They do not always go up the height of the screen--sometimes they are in horizontal bands. If left alone, these bands will eventually become vertical bars with vibrating horizontal lines in them, and they can appear black or psychedelic.

The only way I can fix it is to pull the plug. When I plug it in again, I get the boot screen (Dell logo) and then it works normally for a few minutes. New cables, a different DVI port and/or plugging into another video input on the computer has done nothing. I am running a DVI splitter off the video card so it has a 2nd monitor attached, and it is unaffected. This computer also uses a SEE2 Xtreme external video card for a 3rd monitor, but it also seems unaffected and unplugging it does not help the problem.

I have also checked the diagnostics trick (hold down capacitive buttons 1 and 4) and I can't get it to come up. Probably because the buttons do nothing.

Jeremy