User Guide

Mac Pro (8x) Troubleshooting — General Information 145
the Boot ROM, and SMC updates update the System Management Controller rmware. The SMC
manages fans and other environmental parameters that are independent of the Boot ROM.
Firmware symptoms can be easily mistaken for hardware issues (e.g., overheating issues, fan
noise issues, etc.). Always check both EFI and SMC rmware versions and update if necessary
before replacing any hardware components in the Mac Pro (8x).
The following lists describe the type of symptoms that may be resolved by updating the EFI and
SMC rmware in the Mac Pro (8x).
Symptoms that may be resolved by updating EFI rmware:
Cannot eject media (various conditions)•
No video on start up•
Blue system failure screens in Windows XP/Vista•
Not waking or sleeping when expected•
Bad media taking too long to eject (including holding mouse button down at startup taking •
minutes to eject)
Symptoms that may be resolved by updating SMC rmware:
Fan related behavior (excessive speed or noise)•
Loud audible clicking from some fans•
Thermal shut down or warnings•
Diagnostics reporting failures•
Sleep/wake issues•
Intermittent shut down•
SMC causes bad/missing ambient sensor to cause the computer to go to sleep•
Hangs, black screen on restart from Windows•
Quick power cycle causes Memory Riser Card Diagnostic LEDs & CPU Overtemp LEDs to •
illuminate solidly
Unit does not restart after changing conguration in Expansion Slot Utility•
Please follow the steps outlined in KnowledgeBase article 303364, “About Firmware Updates for
Intel-based Macs,” to perform an EFI and/or SMC rmware update. Information about rmware
versions for Intel Macs can be found in KnowledgeBase article 303880, “Mac OS X: Firmware
Updates for Intel-based Macs.”