Monitor Check

Monitor Check

Overview of display unit
- The display unit communicates with the navigation unit over its own GA-Net bus. Information is sent to the navigation unit whenever the user activates the touch screen, or buttons. Information sent by the navigation unit to the display unit includes commands to control the LCD back light.
- The navigation unit also sends navigation and video information to the screen using the Red, Green, Blue, and Composite Video signals.
- The security system protects the navigation display by daisy-chaining the security signal through it, and then passing the signal to the audio unit.
- The illumination input from the gauge brightness control provides back lighting for the buttons surrounding the screen.




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




RGB Color
This screen verifies that the display unit is receiving the video (R, G, B and Composite sync) signals properly. The three primary colors should all be shown 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. If the picture has lines in it or scrolls horizontally, or vertically, troubleshoot for a Composite sync problem.




Gray Tone
This screen looks for problems with contrast. You should be able to see the changes from bar to bar across the scale. It is normal for the 2 bars on either side to appear the same.




White Raster
The entire display must be white.




Black Raster
The entire display must be black.




Color Pattern
The chart shows the colors being used for the map and menu screens. This is for factory use only. To check the color signal use the "RGB Color" diagnostic found under the Monitor Check.




Monitor Adjustment
This allows you to center the navigation display. Use the joystick to move the picture up/down or left/right. It is unlikely that you will ever need to adjust the monitor position. The "Default" button will reset the display position to factory specifications.




Touch Panel
The panel touch sensing system consists of a touch sensitive resistive membrane covering the display. Contrary to other systems using infrared beams, the screen has to be physically touched to make it work. The display has the capability of an almost infinite number of touch locations. However, to be compatible with earlier systems, the software only senses the locations shown on the diagram screen. Every possible touch button position is shown on this diagram screen. Touching one of these should cause its color to reverse, and sound a "beep". If the touch locations are off slightly (by less than one touch location), use the "Touch Panel Calibration" diagnostic to re-align the touch "zones" with the screen image. If any areas of the screen either don't respond, or respond at some other location when touched, the replace the display unit.




Touch Panel Calibration
Touch the "+" item on the screen. If the screen responds at some other location when touched, adjust the responding point to the touched point using the joy stick.