Power Mac G5: System stops responding

Some Power Mac G5 computers using Mac OS X 10.3 may unexpectedly become unresponsive. For example, the Force Quit dialog box might not appear when you press the Option-Command-Escape keys, and mouse clicks might be ignored.
Many different things could cause an application or the system to become unresponsive, but if you're using a Power Mac G5 with Mac OS X 10.3, you should try the steps presented in this article before spending time on more generalized troubleshooting procedures.

This document addresses a known issue that might cause one or more of these symptoms:
This can happen with any Power Mac G5 that's using Mac OS X 10.3 or later, except Power Mac G5 (June 2004) 2.5 GHz or Power Mac G5 (Late 2004) computers.

Important: If you see a specific application unexpectedly quitting or a kernel panic issue, this document does not apply. See this instead for troubleshooting tips.

Solution

Download and install Mac OS X Update 10.3.6. This update improves general system reliability and addresses these specific symptoms.

Important: If you previously disabled Quartz Extreme while troubleshooting with AppleCare, use these steps to re-enable Quartz Extreme. You can use them before or after installing the update.
  1. Open /Applications/Utilities/Terminal.
  2. Type, on one line:
    defaults delete /Library/Preferences/com.apple.windowserver GLCompositor

  3. Press Return.
  4. Restart the computer.
Published Date: Oct 7, 2016