In the service manual, it is described as bad cooling or a faulty PSU.
If you upgraded the CPU's there is a chance the PSU wont be able to feed the
CPU's enough with power, it does got 900+ W.
But it's all a question of how well the condition is. Will it actually put out the desired watts specified.
Bad cooling can come from faulty cooling compound apply.
Try to check the CPU's and heatsinks if the compound is spread all around.
Also try to change the compound if you are using original. Buy some
Artic silver S 5, costs about ten bucks at a locally PC hardware store.
To start of, check the lights at the RAM's
Push a small button
Remove the computer’s side access panel and observe the diagnostic LEDs, specifically LED
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.
If you could not solve this problem, take it to an Apple store to get help.
Call a cab, the driver is possibly helping you with the luggage, at apple store the driver
is pretty likely helping you carrying it in to the store, other ways the staff will surely help you.
At least in Europe, Sweden. You always being asked for help with luggage when the cab arrives.
"Here is a cut out from my service manual:"
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
1.
Verify power outlet is good.
2. Check that diagnostic LED 2 is on when the power cord is connected.
3. Replace power cord.
4. Check that diagnostic LED 2 is on when the power cord is connected.
5. Reset the logic board. Refer to “Resetting the Logic Board” in this chapter.
6. Verify power supply cables are fully connected.
Mac Pro (Early 2008) Troubleshooting — Symptom Charts 164
7.
Verify that processors are properly seated. Check diagnostic LED 3 and/or LED 4.
8. Verify that processors’ mounting clamps are properly tightened.
9. Test whether the front panel board or power button is at fault. Remove the installed front
panel board and test with a known-good front panel board.
10. Replace front panel board.
11. Replace power button.
12. Replace power supply.
13. Replace logic board.
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
1.
Check diagnostic LED 2 for trickle voltage from the power supply. Refer to “Power Supply
Verification” in this chapter. If verification fails, replace power supply.
2. Verify that the processors are properly seated. Check diagnostic LED 3 and/or LED 4
3. Verify that the processor mounting clamps are properly tightened.
4. Replace the power supply.
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
1.
Reseat video card. (Make sure video card is fully inserted in connector and end of card is
secured by the connector latch.) For video cards that require power cables, check that they
are connected.
2. Reset logic board. Refer to “Resetting the Logic Board” in this chapter.
3. Verify power supply cables are fully connected.
4. Check diagnostic LED 3 and/or LED 4 for processor connection.
5. Reseat processors and check for bent pins.
6. Check diagnostic LED 2 for trickle voltage from the power supply. Refer to “Power Supply
Verification” in this chapter. If verification fails, replace power supply.
7.
Replace logic board.
8. Replace processor.
Power-on LED illuminates when power button is pressed and fans spin
continuously but there is no boot tone or video
1.
Reseat video card. (Make sure video card is fully inserted in connector and end of card is
secured by the connector latch.) For video cards that require power cables, check that they
are connected.
2. Verify speaker cable is fully seated.
Mac Pro (Early 2008) Troubleshooting — Symptom Charts 165
3. Reset logic board. Refer to “Resetting the Logic Board” in this chapter.
4. Check diagnostic LED 3 and/or LED 4 for processor connection
5. If only one of the CPU Error LEDs (LED 3 or 4) comes on, try swapping the processors. If the
Error LED follows the processor to the other processor location, replace that processor.
6. Replace logic board
Power-on LED illuminates when power button is pressed, fans spin, and boot tone
chimes, but there is no video
1.
Verify display is properly connected and powered on.
2. Check video card connector and display cable for any bent pins.
3. Reseat video card. (Make sure video card is fully inserted in connector and end of card is
secured by the connector latch.) For video cards that require power cables, check that they
are connected.
4. Reset PRAM (restart computer while holding down Command-Option-P-R keys until second
boot tone chimes)
5. Reset logic board. Refer to “Resetting the Logic Board” in this chapter.
6. Replace video card
7.
Replace logic board
Power-on LED does not illuminate when power button is pressed, but fans spin,
boot tone chimes, and there is video
1.
Reseat front panel board
2. Replace front panel board
3. Replace logic board
4. Replace power supply
Power-on LED illuminates, fans spin up, no boot tone, and the system shuts down
within a few minutes
1.
Open the side access panel and observe all diagnostic LEDs. Refer to “Diagnostic LEDs” in
this chapter for more information on how to locate and interpret these LEDs. Troubleshoot
further if any LEDs indicate any failure.
2. Reseat the processors and check for bent pins
3. Replace the processors
4. Replace the logic board
5. Replace the power supply
Mac Pro (Early 2008) Troubleshooting — Symptom Charts 166
Fans
Individual fan failure
1.
Verify fan is properly connected.
2. Verify all other fans are working properly. If all fans seem to have failed, the problem is most
likely not the fans. Reset the logic board to see if this resolves this problem.
3. Replace fan
4. Replace logic board
Fans run at high speed (computer may shut down or may just hang and not shut
down as a result)
1.
Check for proper ventilation around the exterior of the computer.
2. If the system is operating normally except for all fans running at full speed, try resetting the
SMC.
3. If the system appears to be hung (unresponsive), then it’s normal behavior for all fans to
ramp to full speed. In this case, troubleshoot any possible operating system, RAM, processor,
logic board, and power supply issues, in that order.
4. Remove the computer’s side access panel and observe the diagnostic LEDs, specifically LED
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.
5. Verify proper processor heat sink installation (see the take apart section for more information
on heat sink installation).
6. Verify all thermal sensors and their cables are properly connected, especially the ambient
temperature sensor board.
7.
Verify all fans are operating properly and are unobstructed, especially the front intake fan.
8. Verify that the proper type of memory is installed. (See “Memory” in the Take Apart chapter
for more information.)
9. Replace power supply.
Computer performance seems sluggish or slow, or computer is completely hung
1.
Start up the computer from a known-good volume, such as its Installation disc, or an external
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.
2. Run Apple Service Diagnostic to verify hardware is functional. Address any diagnostic failures
as necessary.
Mac Pro (Early 2008) Troubleshooting — Symptom Charts 167
3. Check for proper ventilation around the exterior of the computer.
4. Remove the computer’s side access panel and observe the diagnostic LEDs, specifically LED
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.
5. Verify proper processor heat sink installation. (Refer to “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.)
6. Verify all thermal sensors and their cables are properly connected, especially the ambient
temperature sensor board.
7.
Verify all fans are operating properly and are unobstructed, especially the front intake fan.
AirPort Extreme Card
AirPort Extreme Card does not appear to function and is not recognized by
System Profiler
1.
Start up the computer from a known-good volume (such as an external hard drive) with
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.
2. Reseat card and antenna cables connected to card
3. Replace card
4. Replace logic board
AirPort Extreme Card does not appear to function or has weak performance and is
recognized by System Profiler
1.
Start up the computer from a known-good volume (such as an external hard drive) with
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.
2. Reseat card and antenna cables connected to card
3. Replace card
4. Replace logic board
5. Replace AirPort Extreme antenna board / cable assembly
Mac Pro (Early 2008) Troubleshooting — Symptom Charts 168
Bluetooth Card
Bluetooth Card does not appear to function and is not recognized by System
Profiler
1.
Start up the computer from a known-good volume (such as an external hard drive) with
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.
2. Reseat card and antenna cable connected to card
3. Replace card
4. Replace logic board
Bluetooth Card does not appear to function or has weak performance and is
recognized by System Profiler
1.
Start up the computer from a known-good volume (such as an external hard drive) with
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.
2. Reseat card and antenna cable connected to card
3. Replace card
4. If poor signal strength is the issue, replace the Bluetooth antenna board / cable assembly
5. Replace logic board
Other Failures
Optical drive
1.
Try different optical media.
2. If two drives are installed, check the Master/Slave or Cable Select jumpers on both optical
drives (this will depend on drive vendor). Both drives should be set to ‘Cable Select’ mode for
proper operation.
3. If two drives are installed, test one optical drive at a time by disconnecting one of the drives
to see if the other one works.
4. Replace optical drive cable
5. Replace optical drive
6. Replace logic board
Mac Pro (Early 2008) Troubleshooting — Symptom Charts 169
Front Panel FireWire port
1.
Reset SMC.
2. Reseat front panel board cables
3. Replace front panel board cables
4. Reseat front panel board
5. Replace front panel board
6. Replace logic board
Rear FireWire port
1.
Reset SMC.
2. Replace logic board
Front Panel USB 2.0 port
1.
Reseat front panel board cables
2. Replace front panel board cables
3. Reseat front panel board
4. Replace front panel board
5. Replace logic board
Rear Panel USB 2.0 port
Replace logic board
Internal speaker
1.
The Mac Pro (Early 2008) should emit a startup chime through its internal speaker, regardless
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.
2. Check the sound output settings in the Sound preferences to ensure the internal speaker is
selected.
3. Check speaker cable connection
4. Replace speaker
5. Replace logic board
Mac Pro (Early 2008) Troubleshooting — Symptom Charts 170
Audio IO (front headphones)
1.
Start up the computer from a known-good volume (such as its Installation disc or an external
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.
2. Reset PRAM
3. Reseat front panel board
4. Replace front panel board
5. Replace logic board
Audio IO (rear audio line in; rear audio line out)
Note: A red light shines from the rear optical audio-out connector, whether or not a device is
connected to it. This is a normal condition.
1.
Start up the computer from a known-good volume (such as its Installation disc or an external
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.
2. Check Sound settings in System Preferences
3. Reset PRAM
4. Replace logic board
