Power Macintosh G3 (Blue and White) and G4: Memory Errors

This article details a memory issue that may occur on Power Macintosh G3 (Blue and White) and Power Mac G4 computers when a self-powered USB device is attached.


Symptom

If a Power Macintosh G3 (Blue and White) or Power Mac G4 has a self-powered USB device attached, it may experience one or all of the following symptoms:

• After power on, it will not sound a proper startup tone, but instead will sound 3 beeps and no video.
• After startup, you may see an error message stating that the built-in memory test has detected a problem.
• After power on, there will be either no system startup tone or the startup tone will be cut short, and there will be no video.

Moreover, while this issue typically shows up when there is a self-powered USB device connected, the symptom may appear without one connected.

Note: A self-powered USB device is a USB device that has its own power cord and gets its power from an external power source; not from the computer.

Solution

The root cause for this issue has been traced to a particular batch of memory DIMMs, and is greatly exacerbated by the presence of some self-powered USB devices. If your computer is experiencing any or all of the symptoms listed above, your memory DIMMs may need to be replaced. Please contact an Authorized Service Provider to have your computer diagnosed and repaired, if necessary.

Workaround

If your computer is experiencing any or all of the symptoms above and you are unable to have your computer serviced right away, then you can unplug all self-powered USB devices, restart your computer, and then plug back in the USB devices. This will provide a temporary workaround.