Apple mac pro User Manual

Mac Pro Troubleshooting — General Information 151
Memory Riser Card Diagnostic LEDs
Both of the memory riser cards include diagnostic LEDs for each DIMM. Each of the LEDs will 
light if it detects an issue with the corresponding installed DIMM. These LEDs will also flash briefly 
when the computer is started up or shut down and when it goes in and out of sleep mode. This 
is normal behavior.
Troubleshooting: 
Shutdown and restart the computer. • 
Try reseating the DIMMs. • 
Check memory installation...

Mac Pro Troubleshooting — General Information 15 2
Power Supply Verification 
To power on, the computer’s logic board requires “trickle” power. If the system fails to power on, 
first reset the SMC as described in this chapter. If the computer still doesn’t power on, follow the 
procedure outlined below to determine whether the issue is related to the power supply.
Verify trickle power 
Diagnostic LED 1 indicates the presence of trickle power required by the logic board to begin the 
startup process....

Mac Pro Troubleshooting — General Information 15 3
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 firmware:
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...

Mac Pro Troubleshooting — Symptom Charts 154
Symptom Charts
How to Use the Symptom Charts 
The Symptom Charts included in this chapter will help you diagnose specific symptoms related 
to the product. Because cures are listed on the charts in the order of most likely solution, try 
the cures in the order presented. Verify whether or not the product continues to exhibit the 
symptom. If the symptom persists, try the next cure. 
Note: If a cure instructs you to replace a module, reinstall the original...

Mac Pro Troubleshooting — Symptom Charts 15 5
Verify that processors’ mounting clamps are properly tightened. 8. 
Test whether the front panel board or power button is at fault. Remove the installed front 9. 
panel board and test with a known-good front panel board. 
Replace front panel board. 10.  
Replace power button. 11 . 
Replace power supply. 12.  
Replace logic board. 13 . 
Power-on LED illuminates when pressed in, but goes out when button is released, 
there is no boot tone or video, but you can...

Mac Pro Troubleshooting — Symptom Charts 156
Reset logic board. Refer to “3. Resetting the Logic Board” in this chapter. 
Verify power supply cables are properly seated4. .
Check diagnostic LED 2 and/or LED 3 for processor connection 5. 
If only one of the CPU Error LEDs (LED 2 or 3) comes on, try swapping the processors. If the 6. 
Error LED follows the processor to the other processor location, replace that processor.
Replace logic board 7. 
Power-on LED illuminates when power button is pressed, fans...

Mac Pro Troubleshooting — Symptom Charts 15 7
Replace the processors4. 
Replace the logic board 5. 
Replace the power supply 6. 
Fans 
Individual fan failure 
Verify fan is properly connected.1. 
Verify all other fans are working properly. If all fans seem to have failed, the problem is most 2.  
likely not the fans. Reset the logic board to see if this resolves this problem.
Replace fan3. 
Replace logic board 4. 
Fans run at high speed (computer may shut down or may just hang and not shut 
down as a...

Mac Pro Troubleshooting — Symptom Charts 15 8
Remove the computer’s side access panel and observe the diagnostic LEDs, specifically LED 4. 
4 and LED 5 (the CPU A and B Overtemp LEDs). Refer to “Diagnostic LEDs” in this chapter 
for more information on how to locate and interpret these LEDs. If either of these LEDs is 
flashing, this may indicate an initial processor over temperature condition. If either of these 
LEDs is solidly on, this may indicate a chronic processor over temperature condition....

Mac Pro Troubleshooting — Symptom Charts 15 9
Front Panel USB 2.0 port 
Reseat front panel board cables1. 
Replace front panel board cables2.  
Reseat front panel board 3. 
Replace front panel board 4. 
Replace logic board 5. 
Rear Panel USB 2.0 port
Replace logic board 
Internal speaker 
Check speaker cable connection 1. 
Replace speaker2.  
Replace logic board 3. 
AirPort Extreme Card 
Start up the computer from a known-good volume (such as an external hard drive) with 1. 
AirPort driver software...

Mac Pro Troubleshooting — Symptom Charts 160
Reseat front panel board 2. 
Replace front panel board 3. 
Replace logic board 4. 
Audio IO (rear audio line in; rear audio line out) 
Start up the computer from a known-good volume (such as its Installation disc or an external 1. 
hard drive), to isolate the issue to software or hardware. If the computer seems to perform 
adequately when booted in this way, troubleshoot as a software issue. If the computer 
continues to exhibit the issue, follow the steps...