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Last Post 12 Jan 2005 12:13 PM by  mikea@logicpd.com
LCD-6.4 VGA does not light up
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tbeadle
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11 Jan 2005 08:21 AM
    I plugged in my 6.4 VGA display into my LH7a404 SDK and cannot get it to light the LCD backlight. Using the video-open command appears to work (no error messages), but still no backlight. Any ideas?
    mikea@logicpd.com
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    12 Jan 2005 11:55 AM
    tbeadle,
    The typical cause for this is that the card engine is not properly seated onto the SDK board. On the underside of the card engine, there are two white 80-pin connectors. One of these contains all of the LCD signals, including the signal that controls the backlight power on the display kits. If this connector isn't connected properly, the LCD will not function.

    If you believe that the engine is seated properly, the next items to check are that the LCD cable (large ribbon cable) is connected to both the Display Kit and the SDK kit. Both sides should be pushed down all the way so that the connector's "ejectors" are holding down the cable's connector.

    You should also check that the Display Kit's PCB board seems to be attached to the LCD solidly. I can't recall a problem with this, but during shipping, this board could possibly loosen itself enough so that the connection with the LCD is open.

    Let us know if these items have been checked, as almost all issues with Display Kits are mechanical connections.

    Thanks,
    Mike A.
    tbeadle
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    12 Jan 2005 12:06 PM
    Actually, I noticed that one of the two small ribbon cables connected to the LCD backlight power supply was not connected to the panel. When I connected this, problem was solved. These connectors do not "lock" and it probably came off in shipment.
    mikea@logicpd.com
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    12 Jan 2005 12:13 PM
    Ah, that would do it.
    Thanks for responding with your resolution.


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