- Information regarding how to perform a self-diagnosis test procedure may be available in the operating instructions included with your monitor.
- If model-specific information is required to complete any of the steps in this solution, refer to the operating instructions supplied with the monitor. Manuals are posted on your model support page.
- Turn off the monitor.
- Disconnect the video cable that connects the monitor to the computer.
- Ensure the monitor is plugged into a known working AC outlet.
- Turn on the monitor.
- The Power indicator light will turn on and green, and a CABLE DISCONNECTED box will appear with four color bars (red, green, blue and white). This indicates the LCD is functioning properly.
- If the LCD is functioning properly, turn off the monitor, reconnect the video cable that connects the monitor to the computer, then turn on and use the monitor as normal.
- The CABLE DISCONNECTED box may disappear after a few moments, and the Power indicator light may turn red. The self-test can be repeated by pressing the POWER button.
- If the CABLE DISCONNECTED box does not appear while the Power indicator light is green, or if the Power indicator light does not turn on, service for the monitor will be required.  Go to Product Repair.