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 instructions for proper installation order. • 
Swap affected DIMM with known good DIMM.• 
Try moving DIMM to another slot (within the same bank of two) to see if the failure LED • 
follows the DIMM.  If so, replace DIMM with known good DIMM.
Video Card Diagnostic LEDs
The Radeon X1900 XT video card also has diagnostic LEDs. 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
T_Fault LED
Normally off, this LED lights up if the graphics chip gets too hot.
Troubleshooting: 
Check that the front fan is working. • 
Try re-seating the card in the PCI Slot. • 
Make sure the card’s auxiliary booster power cable is connected (if there is one). • 
Re-boot the computer. • 
Try a different video card. • 
Replace the video card.• 
Ext_Power LED
Normally off, this LED lights up if the auxiliary power isn’t being supplied.
Troubleshooting: 
Make sure the card’s auxiliary booster power cable is connected (if there is one). • 
Check connections from the power supply to the logic board. • 
Try a different auxiliary power cable. • 
Try a different video card. • 
Replace the video card.•  
						

							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. 
LED 1 should be yellow when the DIAG_ LED button is pressed, indicating that trickle voltage is 
present.
Verify Power Supply Is Providing Power 
Diagnostic LED 7 indicates that the main power is OK and within regulation. 
Plug in AC power cord, and press the power-on button on the front panel. 
LED 7 should be green when the DIAG_ LED button is pressed, indicating that the main power is 
OK and within regulation.
If diagnostic LED 4 and LED 5 are both solidly illuminated at power up, improperly seated power 
supply cables could be one cause of this behavior. Check all power supply cable connections to 
ensure they are properly seated.
Mac Pro Firmware Updates
Firmware is the name given to software that is written into memory circuits, such as flash 
memory, that will hold the software code indefinitely, even when power is removed from the 
hardware. Firmware on Intel Mac computers is designed to be updated if necessary through a 
software update.
EFI and SMC firmware is stored on the Mac Pro’s logic board. EFI firmware updates update the 
Boot ROM, and SMC updates update the System Management Controller firmware. 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 firmware versions and update if necessary 
before replacing any hardware components in the Mac Pro.
The following lists describe the type of symptoms that may be resolved by updating the EFI and 
SMC firmware in the Mac Pro.
Symptoms that may be resolved by updating EFI firmware:
Cannot eject media (various conditions)• 
No video on start up•  
						

							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 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 configuration 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 firmware update. Information about firmware 
versions for Intel Macs can be found in KnowledgeBase article 303880, “Mac OS X: Firmware 
Updates for Intel-based Macs.” 
						

							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 module before you 
proceed to the next cure. 
Important: The only way to shut off power completely to the computer and display is to 
disconnect their power plugs from the power source. Make sure the power cords to the 
computer and display are within easy reach. 
Startup Failures 
When testing a computer for the following symptoms, remove the side access panel so you can 
better observe or listen for fan movement. 
Note: Be sure to check the “Memory” and “Power-On Self Test” topics in the General Information 
section of this chapter. Incorrect installation of DIMMs or incompatible memory will not allow the 
system to start up correctly. For information on how to correctly install DIMMs, see the “Memory 
(DIMMs)” topic in the Take Apart chapter. 
Important: For troubleshooting purposes, Mac Pro computers may be started up and diagnosed 
with a single processor installed in either the upper (CPU A) or lower (CPU B) position.
Power-on LED does not illuminate when power button is pressed, fans do not 
spin, and there is no boot tone or video 
Verify power outlet is good. 1. 
Check that diagnostic LED 1 is on when the power cord is connected.2.  
Replace power cord. 3. 
Check that diagnostic LED 1 is on when the power cord is connected.4. 
Reset the logic board. Refer to “5. Resetting the Logic Board” in this chapter. 
Verify power supply cables are properly seated. 6. 
Verify that processors are properly seated. Check diagnostic LED 2 and/or LED 3. 7.  
						

							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 hear a small click 
Check diagnostic LED 1 for trickle voltage from the power supply. Refer to “1. Power Supply 
Verification” in this chapter. If verification fails, replace power supply. 
Verify that the processors are properly seated. Check diagnostic LED 2 and/or LED 3. 2.  
Verify that the processor mounting clamps are properly tightened. 3. 
Verify power supply cables are properly seated4. .
Replace the power supply.5. 
Power-on LED illuminates when power button is pressed but fans do not spin (or 
spin only momentarily) and there is no boot tone or video 
Reseat video card. (Make sure video card is fully inserted in connector and end of card is 1. 
secured by the connector latch.) For video cards that require power cables, check that they 
are connected. 
Reset logic board. Refer to “2.  Resetting the Logic Board” in this chapter. 
Verify power supply cables are properly seated3. .
Check diagnostic LED 2 and/or LED 3 for processor connection. 4. 
Reseat processors and check for bent pins. 5. 
Check diagnostic LED 1 for trickle voltage from the power supply. Refer to “6. Power Supply 
Verification” in this chapter. If verification fails, replace power supply. 
Replace logic board. 7. 
Replace processor. 8.  
Power-on LED illuminates when power button is pressed and fans spin 
continuously but there is no boot tone or video 
Reseat video card. (Make sure video card is fully inserted in connector and end of card is 1. 
secured by the connector latch.) For video cards that require power cables, check that they 
are connected. 
Verify speaker cable is fully seated. 2.   
						

							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 spin, and boot tone 
chimes, but there is no video 
Verify display is properly connected and powered on.1.  
Check video card connector and display cable for any bent pins.2.  
Reseat video card. (Make sure video card is fully inserted in connector and end of card is 3. 
secured by the connector latch.) For video cards that require power cables, check that they 
are connected. 
Reset PRAM (restart computer while holding down Command-Option-P-R keys until second 4. 
boot tone chimes) 
Reset logic board. Refer to “5. Resetting the Logic Board” in this chapter. 
Verify power supply cables are properly seated6. .
Replace video card 7. 
Replace logic board 8.  
Power-on LED does not illuminate when power button is pressed, but fans spin, 
boot tone chimes, and there is video 
Verify power supply cables are properly seated1. .
Reseat front panel board 2.  
Replace front panel board 3. 
Replace logic board 4. 
Replace power supply 5. 
Power-on LED illuminates, fans spin up, no boot tone, and the system shuts down 
within a few minutes 
Open the side access panel and observe all diagnostic LEDs. Refer to “1. Diagnostic LEDs” in 
this chapter for more information on how to locate and interpret these LEDs. Troubleshoot 
further if any LEDs indicate any failure.
Verify power supply cables are properly seated2.  .
Reseat the processors and check for bent pins 3.  
						

							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 result)
Check for proper ventilation around the exterior of the computer. 1. 
Remove the computer’s side access panel and observe the diagnostic LEDs, specifically LED 2.  
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 LED is flashing, it may 
indicate an initial processor over-temperature condition. If either LED is solidly on, it may 
indicate a chronic processor over temperature condition.
Verify proper processor heat sink installation (see the take apart section for more information 3. 
on heat sink installation).
Verify all thermal sensors and their cables are properly connected, especially the ambient 4. 
temperature sensor board.
Verify all fans are operating properly and are unobstructed, especially the front intake fan.5. 
Verify that the proper type of memory is installed. (See “6. Memory” in the Take Apart chapter 
for more information.)
Replace power supply.7. 
Computer performance seems sluggish or slow, or computer is completely hung
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 perform sluggishly when booted this way, continue following the steps below.
Run Apple Service Diagnostic to verify hardware is functional. Address any diagnostic failures 2.  
as necessary.
Check for proper ventilation around the exterior of the computer. 3.  
						

							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. Initial 
processor over-temperature can cause symptoms such as sluggish computer performance. A 
chronic processor over-temperature condition can cause the computer to hang completely.
Verify proper processor heat sink installation. (Refer to “5. Processor Heatsinks” in the Take 
Apart chapter for more information.)
Verify all thermal sensors and their cables are properly connected, especially the ambient 6. 
temperature sensor board.
Verify all fans are operating properly and are unobstructed, especially the front intake fan.7. 
Other Failures 
Optical drive 
Try different optical media.1.  
If two drives are installed, check the Master/Slave or Cable Select jumpers on both optical 2.  
drives (this will depend on drive vendor). Both drives should be set to ‘Cable Select’ mode for 
proper operation.
If two drives are installed, test one optical drive at a time by disconnecting one of the drives 3. 
to see if the other one works.
Replace optical drive cable 4. 
Replace optical drive 5. 
Replace logic board 6. 
Front Panel FireWire 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 FireWire port 
Replace logic board  
						

							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 installed, 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 below. 
Reseat antenna cables connected to card 2.  
Replace card 3. 
Replace logic board 4. 
Bluetooth Card
Start up the computer from a known-good volume (such as an external hard drive) with 1. 
Bluetooth driver software installed, 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 below. 
Reseat antenna cable connected to card.2.  
Replace card.3. 
Replace logic board.4. 
Audio IO (front headphones) 
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 below.  
						

							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 below. 
Check Sound settings in System Preferences 2.  
Replace logic board 3.