TITLE
    ColorSync 20-inch Displays: Wave Patterns Across Picture
Article ID:
Created:
Modified: 		34005
5/15/97
5/21/98
TOPIC

    Vibrations from built-in (or external) audio devices can sometimes cause a wave-like shimmering to appear across the ColorSync 20-inch Display screen. This article addresses the causes and cures of this effect.

    Note: The ColorSync 20-inch Display was formerly named the AppleVision 850 Display.

DISCUSSION

    In the AppleVision 850 AV Display (and other AV displays with built-in speakers), vibration from the built-in speakers may sometimes cause the aperture grill on the monitor to vibrate. Aperture grill vibration is visible as a wave-like shimmering on the monitor screen. At normal volumes, this effect should not occur, but at high volume levels it may be noticeable, especially with low-to-mid-range sounds (100-500 hz, most frequent when playing jazz, classical music, male vocalists).

    This effect can also occur on the ColorSync 20-inch Display (formerly known as the AppleVision 850 Display) if external speakers are placed too close to the monitor and played at high volume. To eliminate the problem, move the external speakers further from the monitor and/or reduce the audio volume.

    To eliminate the visual distortion in the AppleVision 850 AV Display , the user should reduce the speaker volume. The audio circuitry monitor is high-powered in order to provide excellent sound quality, not loud volume. Reducing the volume setting will prevent the image from being affected by the sound.

    To minimize the effect on either display at high volume, adjust the rotation of the screen image so that the picture is as level as possible. To adjust the rotation from a Mac OS computer:
      1. Open the Monitors & Sound control panel, then click the Geometry button.
      2. On the Geometry window, click the Rotate button.
      3. Use the position buttons (icons) next to the picture of the monitor to fine-tune the rotation. When the rotation of the screen image is set properly, all four sides of the image are parallel to the edges of the screen and the image is rectangular.

    If using the display with a DOS- or Windows-based computer:
      1. Push any of the control buttons on the left side of the display's front bezel. A control panel will appear on screen.
      2. Press the < or > control button until the Geometry menu is selected.
      3. Press the V control button until Rotate is selected.
      4. Press the - button to rotate the screen image counterclockwise or the + button to rotate it clockwise. When the rotation of the screen image is set properly, all four sides of the image are parallel to the edges of the screen and the image is rectangular.

Document Information
Product Area: Monitors-Displays
Category: Multiple Scan Displays
Sub Category: ColorSync 20-inch Displays

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