User Guide

Power Mac G4 Cube Troubleshooting - 5
General Information
ROM and Processor Verification: Power-On Self Test
The ROM of the Power Mac G4 Cube computer contains a self test that runs whenever the
computer is turned on after having been shut down. It does not run if the computer is only
restarted. If a potential issue is detected during the test, you will not hear a startup sound;
instead, you will see the power-on light flash two, three, or four times.
Note: In this case, a flash is considered to be 1/4 second or 250 ms or greater in length.
If you do not hear a startup sound, the power-on light will flash as explained below:
Two Flashes: No memory is installed or detected
If memory is installed, ensure it is seated properly, as follows:
1. Shut down the computer by holding down the power button (about 5 sec.) until it shuts
off. Then disconnect the power cord from the computer.
2. Remove the computer core.
3. Rotate the core so you can see the memory.
4. Eject and reinsert the memory to ensure the memory is seated properly.
5. After reseating the memory, replace the core in the enclosure.
6. Plug in all the cables, and turn on the computer.
7. If the light still flashes, contact Apple Support for assistance.
If no memory is installed, install compatible memory, as follows:
8. Shut down the computer by holding down the power button (about 5 sec.) until it shuts
off. Then remove the power cord from the computer.
9. Remove the computer core.
10. Rotate the core so you can see the memory slots.
11. Install compatible memory. Refer to the Power Mac G4 Cube owner's manual, which
discusses the type of memory that is compatible with the computer. You can also refer
to http://www.apple.com/guide/, and Knowledge Base article 58776: "Power Mac G4
Cube: Memory Specifications".
12. After installing memory, reassemble the computer and test for the symptom.