Using Dell's Built-in Flat Panel Display Diagnostics If you have attempted a Factory Reset, and your Dell flat Panel is still displaying: Distorted colors, brightness, lines, jittering or a blank screen, we can utilize diagnostics built into your Dell flat panel to help identify the cause.
These diagnostics can help us identify whether the fault lies with the flat panel itself, or the video source without the need for swapping another display, or changing any settings on your computer. The first test will verify the basic functionality of the monitor.
To initiate the Floating Self Test box, turn the monitor off, and disconnect all cables except for power. Once the monitor is isolated to a power cable only, turn the monitor on. If the monitor is functioning properly, you should now see a Self Test Box slowly floating around the screen.
The box should be free from the distortion you have been experiencing. If the Floating Self Test Box does not appear, or is distorted in any way, your flat panel monitor has experienced a failure and will need to be serviced or replaced.
If the Self Test Box appears to be free from distortion, we can further verify the functionality of the monitor by running the Built-In Self Test, which will verify the red, green and blue sub pixels of the monitor. With the Floating Self Test Box on the screen, press your monitor's "Menu" and "Up", or "+" button. This is usually buttons 1 and 4 on most Dell Flat Panels.
For information specific to your Flat Panel, User's Guides are available on Dell.com/support in the Manuals and Documentation section. The display buttons must be pressed and held simultaneously. If initiated properly, the screen should turn gray. If you receive a menu instead, you will need to exit the menu, and retry from the Floating Self Test Box.
Once you have reached the gray screen, press the 1, or + button, to cycle through the red, green and blue sub pixel screens. The next screen will be all off - black. Followed by all on - white. Some Dell monitors may have a final text screen, which should be black text on a white background on the top, and white text on a black background on the bottom. The color screens should be free from any defects, and should be uniform in brightness.
If they are, this indicates that the video distortion you are experiencing is initiating from the video source, which could be your computer, cabling or any adapters being used.
If any of the screens are distorted, your flat panel monitor has experienced a failure and may need to be serviced or replaced. For assistance in having your Dell monitor serviced or replaced, you may contact Dell Technical Support.