GPS screen red and only red


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Riot13
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GPS screen red and only red

Post by Riot13 » Tue Aug 13, 2019 12:34 pm



The navigation screen is red. I want to see if anyone else has had this problem and if so what is the fix.

Looks to be either the screen or the navigation unit in the trunk.
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WingAdmin
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Re: GPS screen red and only red

Post by WingAdmin » Tue Aug 13, 2019 2:05 pm

Unlike most digital screens, where a computer sends a digital stream of data to the LCD, and the computer built into the LCD plots the data onto the screen as an image, the Goldwing LCD works differently. The computer actually encodes the image as ANALOG VIDEO, and sends it as RGB (much like a VGA connection on a computer monitor) to the screen. The screen, instead of being an intelligent computer itself capable of decoding a data stream, instead is just a dumb monitor that shows whatever is being sent to it. I don't know what video format they use, but I would not be at all surprised if it standard VGA - i.e. you could plug any computer video signal into that connector and have it show up on the screen.

Here's the schematic:

LCD circuit
LCD circuit

Why is this important: Because it is analog, it means if you disconnect one of the color signals, that color will vanish from the screen - but the remaining colors will still be shown.

If you have a screen showing all white (which is made up of red, green and blue pixels), and you disconnect the green wire, the formerly white image will instead show up as purple (which is red and blue combined).

If you have an image showing red, green and blue bars, and you disconnect the red wire, the green and blue bars will remain, but where the red bars were, will instead be black.

So what I think has happened is that the green and blue wires are either broken/disconnected or damaged - either in one of the connectors, or in the harness. The only signal still getting through to the display is red, which is why you're seeing red things only.

Riot13
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Re: GPS screen red and only red

Post by Riot13 » Tue Aug 13, 2019 4:17 pm

Thank you for the post confirming what I thought... is there a way to detect a signal output from the navigation unit with a volt meter or scope. What should I see on the rgb wires?

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AZgl1800
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Re: GPS screen red and only red

Post by AZgl1800 » Wed Aug 14, 2019 4:13 am

Riot13 wrote:
Tue Aug 13, 2019 4:17 pm
Thank you for the post confirming what I thought... is there a way to detect a signal output from the navigation unit with a volt meter or scope. What should I see on the rgb wires?
If you have access to an Oscilloscope, you can monitor the data on each of the RGB lines.
That way you would be able to have a "Go, no go" bit of information as to IF that signal line is good.

You won't be able to interpret what you see, but you will know that information is being sent to the display.
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GoldWingrGreg
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Re: GPS screen red and only red

Post by GoldWingrGreg » Wed Aug 14, 2019 7:02 am

Are you aware that there are color settings for that in you Set-Up screens.

If that does not work, got some Battle-Vision glasses as seen on TV.

https://www.carolwrightgifts.com/battle ... =ASTV_0000

Riot13
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Re: GPS screen red and only red

Post by Riot13 » Wed Aug 14, 2019 9:56 am

I have already tried the screen options in the menu with no results. I am currently on a road trip when this problem occured and once I get back home I will do some diagnostic work.
I will most likely try some continuity tests in the wire harness leading to the GPS unit from the connector under the seat.

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WingAdmin
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Re: GPS screen red and only red

Post by WingAdmin » Wed Aug 14, 2019 12:31 pm

Keep in mind that these are ANALOG signals. So if the wire or connector has some resistance but lets SOME signal through, the end result will be less of that color displayed on the screen. A continuity test might say "yup, there is continuity" but a better test might be a resistance test - you want as close to 0 ohms as possible over the length of each wire, from connector to connector.



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