Apple mac pro early 2008 User Manual

							Mac Pro (Early 2008) Troubleshooting — General Information 161
Processor Heatsink and Processor Visual Inspection Instructions
The Mac Pro (Early 2008 Dual 3.2 GHz) computer uses a special coating on the processor 
heatsink and processor to manage the temperature in the computer. Before installing a new or 
existing heatsink or processor, always make a visual inspection of the part. Specifically, check 
the application of the silver-colored coating on the underside of the heatsink and the top of 
the processor. In addition, check the condition of the gasket that surrounds the coating on the 
heatsink.
Important: When inspecting the special coating, wear disposable nitrile or latex gloves and avoid 
touching the coating. 
Silver-Colored Coating on Heatsink and Processor
Use the following guidelines to determine if the silver-colored coating on the underside of the 
heatsink and the top of the processor is correctly applied. If a new, replacement heatsink or 
processor fails to meet the prescribed standards, return it to Apple. If an existing heatsink or 
processor fails the standards, replace it with a new part before installing it in the computer.
Acceptable standard
The silver-colored coating should be applied in a smooth, even square as show below. 
						

							Mac Pro (Early 2008) Troubleshooting — General Information 162
Unacceptable examples
The following are examples of unacceptable applications of the coating. Return new parts or 
replace existing parts that exhibit similar applications. 
Void IVoid IISplash
Void I: The silver-colored coating shows missing areas of within the normal coated area.
Void II: The silver-colored coating shows missing areas along the edge of the coated area.
Splash: The silver-colored coating extends beyond the normal coated area.
Important: If you observe a heatsink or processor with a “splash” of special coating, first try to 
remove the excess by using the method described below under “Removing Stray Particles of 
Coating.” If this approach does not remove the splash, return the part to Apple.
Removing Stray Particles of Coating
In rare cases, small particles or beads of the silver-colored coating may appear outside the normal 
coated area of a replacement heatsink or processor. You must remove these particles before 
installing the part. Failure to do so could result in damage to the part or the logic board. 
						

							Mac Pro (Early 2008) Troubleshooting — General Information 16 3
To remove the particles, use the suction pipette that comes with the replacement heatsink and 
processor. ( The pipette is also available through GSX as part of the Mac Pro Grease Kit, part 
number 076-1258.) Depress the bulb end of the pipette, place the other end over the particle, 
and release the bulb. The particle will be suctioned into the pipette. 
Once you have removed all stray particles, place the pipette inside the resealable bag included 
with the replacement part. Pack this bag along with the failed part in the box that the 
replacement part came in, and return the box to Apple.
Gasket on Heatsink
Check that the gasket that surrounds the silver-colored coating on the underside of the heatsink 
is in good condition, as shown below.
Replace the gasket if it shows obvious damage, such as cracks, folds, and broken-off surfaces, or 
if it is dislocated from the heatsink. The gasket is available through GSX as part of the Mac Pro 
Grease Kit, part number 076-1258. 
						

							Mac Pro (Early 2008) Troubleshooting — Symptom Charts 16 4
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 (Early 2008) 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 2 is on when the power cord is connected.2.  
Replace power cord. 3. 
Check that diagnostic LED 2 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 fully connected. 6.  
						

							Mac Pro (Early 2008) Troubleshooting — Symptom Charts 165
Verify that processors are properly seated. Check diagnostic LED 3 and/or LED 4. 7. 
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 2 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 3 and/or LED 4 2.  
Verify that the processor mounting clamps are properly tightened. 3. 
Replace the power supply.4. 
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 fully connected. 3. 
Check diagnostic LED 3 and/or LED 4 for processor connection. 4. 
Reseat processors and check for bent pins. 5. 
Check diagnostic LED 2 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 (Early 2008) Troubleshooting — Symptom Charts 166
Reset logic board. Refer to “3. Resetting the Logic Board” in this chapter. 
Check diagnostic LED 3 and/or LED 4 for processor connection 4. 
If only one of the CPU Error LEDs (LED 3 or 4) comes on, try swapping the processors. If the 5. 
Error LED follows the processor to the other processor location, replace that processor.
Replace logic board 6. 
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. 
Replace video card 6. 
Replace logic board 7. 
Power-on LED does not illuminate when power button is pressed, but fans spin, 
boot tone chimes, and there is video 
Reseat front panel board 1.  
Replace front panel board 2.  
Replace logic board 3. 
Replace power supply 4. 
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.
Reseat the processors and check for bent pins 2.  
Replace the processors3. 
Replace the logic board 4. 
Replace the power supply 5.  
						

							Mac Pro (Early 2008) Troubleshooting — Symptom Charts 16 7
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. 
If the system is operating normally except for all fans running at full speed, try resetting the 2.  
SMC.
If the system appears to be hung (unresponsive), then it’s normal behavior for all fans to 3. 
ramp to full speed.  In this case, troubleshoot any possible operating system, RAM, processor, 
logic board, and power supply issues, in that order.
Remove the computer’s side access panel and observe the diagnostic LEDs, specifically LED 4. 
5 and LED 6 (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 5. 
on heat sink installation).
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. 
Verify that the proper type of memory is installed. (See “8.  Memory” in the Take Apart chapter 
for more information.)
Replace power supply.9. 
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. 
						

							Mac Pro (Early 2008) Troubleshooting — Symptom Charts 168
Check for proper ventilation around the exterior of the computer. 3. 
Remove the computer’s side access panel and observe the diagnostic LEDs, specifically LED 4. 
5 and LED 6 (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 for 2.8 and 3.0 
GHz Processors” or “Processor Heatsinks for 3.2 GHz Processors” 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. 
AirPort Extreme Card
AirPort Extreme Card does not appear to function and is not recognized by 
System Profiler
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 card and antenna cables connected to card 2.  
Replace card 3. 
Replace logic board 4. 
AirPort Extreme Card does not appear to function or has weak performance and is 
recognized by System Profiler
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 card and antenna cables connected to card 2.  
Replace card3. 
Replace logic board4. 
Replace AirPort Extreme antenna board / cable assembly5.  
						

							Mac Pro (Early 2008) Troubleshooting — Symptom Charts 16 9
Bluetooth Card
Bluetooth Card does not appear to function and is not recognized by System 
Profiler
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 card and antenna cable connected to card2.  
Replace card3. 
Replace logic board4. 
Bluetooth Card does not appear to function or has weak performance and is 
recognized by System Profiler
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 card and antenna cable connected to card 2.  
Replace card3. 
If poor signal strength is the issue, replace the Bluetooth antenna board / cable assembly4. 
Replace logic board5. 
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.  
						

							Mac Pro (Early 2008) Troubleshooting — Symptom Charts 170
Front Panel FireWire port 
Reset SMC.1. 
Reseat front panel board cables2.  
Replace front panel board cables3. 
Reseat front panel board 4. 
Replace front panel board 5. 
Replace logic board 6. 
Rear FireWire port 
Reset SMC.1. 
Replace logic board 2.  
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 
The Mac Pro (Early 2008) should emit a startup chime through its internal speaker, regardless 1. 
of whether headphones or external speakers are connected.  If you hear a normal startup 
chime, but no other audio is produced from the internal speaker, and there is nothing 
connected to either audio-out port, suspect a damaged front panel headphone port or rear 
audio-out port.  In this case, replace the front panel board or logic board as necessary.  If you 
do not hear a startup chime through the internal speaker, even after resetting PRAM, follow 
the steps below.
Check the sound output settings in the Sound preferences to ensure the internal speaker is 2.  
selected.
Check speaker cable connection 3. 
Replace speaker4. 
Replace logic board 5.