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Power Mac G5 uniprocessor firmware update: System instability for 1.6 GHz models

Power Mac G5 uniprocessor firmware update: System instability for 1.6 GHz models

CNET staff
2 min read

System instability for 1.6 GHz models A fairly large number of readers are reporting significant system instability on Power Mac G5 1.6 GHz models after applying the Power Mac G5 5.1.5f1 firmware update.

One reader writes "The update appears to work fine but 1.6 GHz systems become unstable almost to the point of being unusable. Crashing repeatedly after approx. 5 or 6 minutes of use, even on machines that have never crashed prior to the update."

Some users have found that running the Apple Hardware test CD reveals a memory error, indicating that the firmware update may increase sensitivity to problematic RAM modules. Try removing non-Apple RAM from your system, or moving the modules to different sockets (faster-rated RAM in the lower sockets) and see if it makes a difference.

Other than removing bad RAM modules, however, there does not seem to be a solid workaround to this issue. It is impossible to revert firmware versions.

More on installation problems Meanwhile, users continue to report problems installing the update.

MacFixIt reader Jeffrey Fingar writes "I had to restart my SP 1.8 G5 4 times to get it back to normal. It kept wanting to be in the Open Firmware mode and typing in 'mac-boot' as instructed was not making the re-boot to happen. I was about to unplug all USB devices, but on the fourth re-boot it finally fixed itself."

If you are experiencing issues similar to Jeffrey's, you may need to reset your G5's PRAM, and then perform a "reset-all" command as described in Apple Knowledge Base article #42642.

Feedback? Late-breakers@macfixit.com.

Resources

  • Power Mac G5 5.1.5f1
  • #42642
  • Late-breakers@macfixit.com
  • More from Late-Breakers