Monitor Check: Notes

Overview of the navigation display unit

• The navigation display unit communicates with the audio-navigation unit over its own GA-Net bus. Information sent by the audio-navigation unit to the navigation display unit includes commands to control the LCD back light.
• The security system protects the navigation display unit by daisy-chaining the security signal through the components.

These diagnostic screens allow you to troubleshoot the navigation display unit. Select the item you want to troubleshoot, and follow the diagnostic instructions.

RGB Color 

This diagnostic screen checks that the navigation display unit is receiving the video (R, G, B, and Composite sync) signals properly. The three primary colors should all appear without distortion. The combination of all three should produce a central white section. If any of the colors are missing, troubleshoot for the color signal (see PICTURE IS MISSING A COLOR OR TONE OR IS AN ODD COLOR  ). If the picture has lines in it or scrolls horizontally, or vertically, troubleshoot for a Composite sync problem (see PICTURE HAS LINES, ROLLS, OR IS BLURRY  ).