If the Extensions Manager is set to "Mac OS 8.5 All", or the set of extensions that loads at startup are otherwise customized, it is possible that switching the monitor's resolution yields a blank gray screen and the mouse pointer seems to disappear.

If the necessary support files an extension needs to load have been disabled, a red X will appear over its icon during startup, indicating the extension did not load properly.

In Power Macintosh G3 (Blue and White) computers that ship with Mac OS 8.5.1, some of the ATI video driver extensions are part of the Mac OS 8.5 package, and some are part of the Power Macintosh G3 2.0 package. When selecting Mac OS 8.5 All, extensions that are not part of this set do not load, including the ATI Resource Manager extension. As a result, the ATI software will not completely load, and you may see a blank gray screen after switching resolutions.

If this situation occurs, you may need to restart the computer using the reset button (with the triangle symbol) on the front of the computer. Video is restored after restart.

To resolve the situation, enable all of the ATI extensions using the following steps:

1. In the Extensions Manager and choose View as Packages from the View menu.

2. Choose Mac OS 8.5 All from the Selected Set popup menu.

3. Check the checkbox next to the Power Macintosh G3 2.0 package to ensure all ATI extensions are enabled. (Make sure the checkbox has an "x" in it, not just a "-".)

4. Restart the computer.