Apple M8347LL/A User Guide - Page 170

Troubleshooting Symptom/Cure Tables: System Problems After Startup - 38 Can't Wake From Sleep The computer cannot be brought out of "sleep" mode by pressing a key on the keyboard. The problem is usually evident by a black screen and a pulsing amber LED. Possible Cause Possible Fix PMU Bad keyboard Corrupted PRAM Software Conflict Bad logic board Press the PMU chip on the logic board with the AC power cord disconnected. (See "The PMU Chip" and "Resetting the PMU on the Logic Board" mentioned earlier in this chapter.) Connect the power cord and power on the system again. Do you have power to the system now? Yes: Test the unit with MacTest Pro and return the computer to the customer. No: Plug in the AC power cord and reset the PMU chip again. Do you have power to the system now? Yes: The battery is likely bad, check the battery. No: Go to the next step. Try a known-good keyboard. Reset the PRAM by holding down the Option-Command- P-and R keys Reinstall System Software. You must use the system software that came with the unit in order to get the correct version of Mac OS. Note: If the computer sleeps while connected to the Internet, and is running Mac OS 8.6 or Mac OS 9.0, download Apple Audio Update 1.3 from the Apple Software Update page. Replace the logic board.