A set of vertical lines appear onscreen for about the first 30 minutes after the PC/monitor are turned on. The attached JPGs show the complete screen and a close-up of the lines. Ignore the greenish horizontal band - that is an artifact of taking a picture of the computer screen. After about a half hour the lines disappear for as long as the PC is left on. (It is turned off each night.)
The lines occur at about 89.9% across the screen from the left edge or about horizontal pixel 1725 of 1900.
I'd like to figure out how to eliminate the vertical lines.
The lines do NOT show up in a screen capture. They must be generated in the hardware. The attached images were taken with a camera.
The PC is a Dell Precision Work Station 370 running Windows XP SP3. The monitor is a Dell 2709W active matrix TFT LCD. The monitor runs at its native 1900x1200 32-bit color mode.
I think it is something inside the PC. I've seen similar bars using the same PC with two different graphics cards (one ATI and one nVidia) and two different Dell monitors.
I have tried resetting the monitor to its factory defaults - no effect.