AppleVision or ColorSync Display: Only resolution is 640x480

After connecting an AppleVision 1710 display to the Power Macintosh 7500/100 onboard video port, the only available resolution is 640x480. Also, the sound controls do not seem to work.

The speaker and microphone cables from the monitor are connected to the corresponding ports on the Power Macintosh. I am not using the ADB connector for the monitor because I wanted to connect the keyboard directly to my Macintosh computer.
The AppleVision or ColorSync Display software uses the ADB cable to sense what kind of monitor is connected to the computer. If the integrated ADB/video cable is not used, the only resolution available is 640x480 and the speaker controls on the front of the monitor will not bring up their corresponding control strip modules. The volume and tone buttons work, but you do not see the levels on your monitor control strip.

If the AppleVision or ColorSync Display is connected without the ADB connector to a Macintosh previously using a display at a resolution higher than 640x480, the monitor displays the higher resolution during the startup process. However, when the desktop displays the resolution resets to 640x480 and does not offer you the ability to change the resolution.

Solution:
Use the integrated ADB/video cable and restart your Macintosh.

If you are still only getting the 640 x 480 resolution, follow the troubleshooting steps below.

Troubleshooting Steps

  1. Verify that all cables are securely connected.
  2. Verify that the AppleVision or ColorSync extension is installed and loading at startup.
  3. Delete the preferences for the Finder and one or more of the following:
    • Sounds & Displays prefs
    • Monitors & Sound prefs
    • Monitors
    • Sound Preferences

      Depending on the computer and version of Mac OS installed you will find one or more of these preference files in your Preferences folder, which is located inside your System folder.

  4. Remove the existing AppleVision or ColorSync software from the Extensions folder and discard it. (The file will be named "AppleVision" and may be preceded by a degree sign.)
  5. Install the latest version of AppleVision or ColorSync Display software from Apple Downloads.
Published Date: Feb 19, 2012