System 7.5: Some Multiple Scan Displays Show One Size

After installing Sytem 7.5 on a Macintosh Quadra 840AV, the Multiple Scan Display only allows a screen resolution of 640x480.
The problem you are seeing is due to additional portions of the Display Enabler functionality added to System 7.5. If you use the Display Enabler with System 7.1, you have the same problem.

Workaround

Hold down the Option key while clicking on the Options button in the Monitors control panel. Holding down the Option key forces the Macintosh to display all available resolutions.

This issue only occurs on Macintosh Centris/Quadra 660AV and Quadra 840AV computers.

Published Date: Feb 19, 2012