Apple mac pro 8x User Manual

							Mac Pro (8x) Take Apart — Power Cable Harness 131
Untape the power harness cable from the enclosure. 7. 
Remove the power harness cable from its routing along the edge of the logic board, over the 8.  
speaker assembly, and along the bottom lip of the enclosure. 
Remove the power harness cable from the enclosure.9.  
						

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 Service Source 
Troubleshooting
Mac Pro (8x) 
						

							Mac Pro (8x) Troubleshooting — General Information 13 3
General Information
Memory
The Mac Pro (8x) computer has two memory cards with a total of 8 memory slots. On each card, 
the slots are arranged as two banks of two slots each. The computer comes with a minimum of 
1 GB of memory, installed as a pair of 512 MB fully buffered, dual inline memory modules (FB-
DIMMs) in two of the DIMM slots. Additional DIMMs can be installed in the open DIMM slots, as 
illustrated below.
Note: DIMMs must be installed in pairs of equal size from the same vendor. In the following 
illustration, DIMMs in one colored pair do not need to match DIMMs in a different colored pair. 
						

							Mac Pro (8x) Troubleshooting — General Information 134
DIMMs for Mac Pro (8x) must fit these specifications:
667 MHz, FB-DIMMs• 
72-bit wide, 240-pin modules• 
36 devices maximum per DIMM• 
Error-correcting code (ECC)• 
Important: For proper operation of Mac Pro (8x) computers, Apple recommends using only 
Apple-approved Mac Pro (8x) FB-DIMMs. Refer to GSX for Apple FB-DIMMs service part numbers.
PCI Express Cards
The Mac Pro (8x) logic board includes one double-wide PCI Express graphics slot and three 
PCI Express expansion slots, for a total of four slots. The computer comes with a graphics card 
installed in slot 1. You can install additional PCI Express graphics and expansion cards in the 
remaining three PCI Express expansion slots.
Important: Combined maximum power consumption for all four PCI Express slots must not 
exceed 300 W.
Slot 1: Double-wide
PCI Express graphics
(graphics card installed) Slots 2–4: PCI Express
Internal Cabling Matrix
The table on the next page lists all Mac Pro (8x) internal cables that connect to the logic board 
and are not part of a larger subassembly. Following the table is a map of the logic board 
connector locations, which are listed in column 5 of the table. 
						

							Mac Pro (8x) Troubleshooting — General Information 13 5
M43a Int Cable Matrix Rotated.xls
CONDIFENTIAL - NEED T O KNOW ONLY
Cable, Connector and Signal MatrixCABLE DESCRIPTION
Service PN
LENGTH (mm)
LENGTH (in)
MLB CONN LOCATION
MLB CONN LABEL
MLB CONN DESCRIPTION
CONNECTOR 2 DESCRIPTION
CONNECTOR 3 DESCRIPTION
CONNECTOR 4 DESCRIPTION
CONNECTOR 5 DESCRIPTION
POWER / SIGNALS CARRIED
HDD SATA
P art of 922-7682
450
17.7
C -1
SATA
36-pin high-densit y
7-pin flat to HDD 1
7-pin flat to HDD 2
7-pin flat to HDD 3
7-pin flat to HDD 4
Serial A TA signals to/from all four HDDs and main logic board
HDD P ower
Part of 922-7682
442
17.4
A -1
HDD_PWR
8-pin (2X4)
15-pin flat to HDD 1
15-pin flat to HDD 2
15-pin flat to HDD 3
15-pin flat to HDD 4
DC power to all four HDDs from main logic board
HDD Thermal Sensor
922-7730
610
24.0
A-2
HDD_SNS
4-pin flat (4X1)
7-pin flat to sensor bd underneath HDD 1
7-pin flat to sensor bd underneath HDD 2
7-pin flat to sensor bd underneath HDD 3
7-pin flat to sensor bd underneath HDD 4
Thermal sensor signals from sensors in all HDD ba ys to main logic board
Optical Drive Power
922-7684
559
22.0
B-1
ODD_PWR
4-pin square (2X2)
standard 4-pin (4x1) to upper ODD
standard 4-pin (4x1) to lower ODD
DC power to both optical driv es from main logic board
Optical Drive IDE
922-7686
586
23.1
D-1
OPTICAL
40-pin standard IDE (20X2)
Standard 40-pin IDE for lower ODD
Standard 40-pin IDE for upper ODD
IDE signals to/from all optical drives and main logic board
Power Supply PS #1
922-8059
1033
40.7
K -6
none
Large 10-pin (5X2)
Large 10-pin (5x2) from PS labeled PS#1
DC power to main logic board from power supply
Power Supply PS #2
922-8060
469
18.5
J-1
none
Large 10-pin (5X2)
Large 10-pin (5x2) from PS labeled PS#2
DC power to main logic board From power supply
Power Supply PS #3
922-8061
273
10.7
B -1
none
Large 12-pin (6X2)
Large 12-pin (6x2) from PS labeled PS#3
DC power to main logic board From power supply
Power Supply Control PS # 4
922-8030
1083
42.6
K -6
none
Medium 10-pin (5X2)
Large 10-pin (5x2) from PS labeled PS#4
Power supply control signals to/from main logic board
Front P anel Board P ower 
922-7690
860
33.9
K-7
FP_MISC
Medium 8-pin (4X2)
Medium 8-pin (4x2) on top of FP bd
Power , power LED , power button, and control signals to the front panel board from the main logic board
Front Panel Board A udio
922-7692
865
34.1
J-9
FP_AUDIO
Small sidew ays 5-pin (5X1)
Small sidew ays 5-pin on top of FP bd
A udio signals to the front panel board from the main logic board
Front P anel Board FireWire-800
922-7691
695
27.4
K-7
FP_FWB
9-pin sidew ays standard FW800
9-pin sidew ays standard FW800 on bottom of FP bd
Standard FW800 9-pin to 9-pin cable to front panel board from main logic board
Front P anel Board USB
922-7693
150
5.9
C-2
FP_USB
Small 7-pin rt angle (7X1)
Small 7-pin rt angle in middle of FP bd
USB 2.0 power and data to front panel board from main logic board
Intak e Ambient T emperature Sensor
922-7731
400
15.7
B-2
ODD_SNS
Small 4-pin (4X1)
Small 7-pin on  thermal sensor bd inside top of ODD ba y
Thermal sensor signals from ODD bay ambient temp sensor to main logic board 
						

							Mac Pro (8x) Troubleshooting — General Information 13 6
Cable Connector Locations
Use the diagram below to find the location of the internal cable connectors on the logic board.
A        B       C        D        E        F        G       H        J   \
      K
A 
       B       C        D        E        F        G       H        J   \
      K
1 2 3 4 5 6 7 8 9
12 3 4 5 6 7 8 9
Thermal Calibration
Unlike in earlier Power Mac G5 computers, replacing a processor in a Mac Pro (8x) computer does 
not require running Apple Service Diagnostic for thermal calibration. 
						

							Mac Pro (8x) Troubleshooting — General Information 13 7
Resetting the Logic Board
System Management Controller (SMC) Reset
The System Management Controller (SMC) is a chip on the logic board that controls all power 
functions for the computer. If the computer is experiencing any power issue, resetting the SMC 
may resolve it. The SMC controls several functions, including:
Telling the computer when to turn on, turn off, sleep, wake, idle, and so forth• 
Handling system resets from various commands• 
Controlling the fans• 
It is also recommended that the SMC be reset after a logic board, ambient board, or ambient 
board cable is replaced as part of a repair.
Note that resetting the SMC does not reset the PRAM. Resetting the SMC will not resolve issues in 
which the computer is unresponsive—in these situations, restarting the computer will generally 
suffice. If the computer isn’t responding, perform these steps one at a time, in the following order, 
until the issue has been resolved:
Force Quit (Option-Command-Escape)1. 
Restart (Control-Command-Power)2.  
Force Shut Down (press the power button for 10 seconds)3. 
Resetting the SMC can resolve some computer issues such as not starting up, not displaying 
video, sleep issues, fan noise issues, and so forth. If the computer still exhibits these types of 
issues after you’ve restarted the computer, try resetting the SMC. There are two ways to reset the 
SMC on Mac Pro (8x).
You can use the SMC reset switch:
From the Apple menu, choose Shut Down (or if the computer is not responding, hold the 1. 
power button until it turns off ).
Press the SMC_RST switch, which is located to the right and slightly below the row of 2.  
diagnostic LEDs. (See the LED diagram in the following “Diagnostic LEDs” section.) To press 
the switch, use the nylon probe tool (Apple part number 922-5065).
Press the power button to start up the computer.3. 
Or, you can reset the SMC by removing AC power:
From the Apple menu, choose Shut Down (or if the computer is not responding, hold the 1. 
power button until it turns off ).
Unplug the AC power cord.2.  
Wait at least 15 seconds.3. 
Plug the power cord back in, making sure the power button is not being pressed at the time. 4. 
Press the power button to start up the computer.5.  
						

							Mac Pro (8x) Troubleshooting — General Information 13 8
Real Time Clock (RTC) Reset
The Real Time Clock (RTC) is a chip on the logic board that controls the date and time functions 
of the computer. If the computer is experiencing an issue booting, resetting the RTC may resolve 
it. Follow these steps to reset the RTC:
From the Apple menu, choose Shut Down (or if the computer is not responding, hold the 1. 
power button until it turns off ).
Unplug the AC power cord.2.  
Remove the battery for at least 20 seconds. You may need to remove a PCI Express card to 3. 
have access to the battery. 
System Reset
Mac Pro (8x) has a system reset switch on the logic board that may be used to restart the 
system while it is powered up. This switch can be used to determine if a computer that won’t 
consistently boot from a cold start has power supply issues. Follow these steps to reset the 
system:
With the computer powered up, press the SYS_RST switch located in the upper right-hand 1. 
corner of the logic board. To press the switch, use the nylon probe tool (Apple part number 
922-5065).
If the computer boots after you press the SYS_RST switch, try shutting the computer off and 2.  
restarting by pressing the front power button. If the computer restarts when you press the 
SYS_RST switch but not from a cold start, the power supply may need to be replaced. 
Power-On Self Test: RAM and Processor Verification
A power-on self test in the computer’s ROM automatically runs whenever the computer is started 
up after being fully shut down (the test does not run if the computer is only restarted). If the test 
detects a problem, the status LED located above the power button on the front of the computer 
will flash in the following ways*: 
1 Flash: No RAM is installed or detected. Or, the quick memory test failed. An LED will light up • 
on the memory riser card next to the affected DIMM or empty DIMM slot.
3 Flashes: A RAM bank failed extended memory testing. An LED will light up on the memory • 
riser card corresponding to the affected DIMM.
Troubleshooting: Try reseating the memory DIMMs. Check memory installation instructions for 
proper installation order. Swap affected DIMM with known good DIMM.
*Note: The status LED lights up when the power button is depressed at startup. Do not count this 
light as one of the diagnostic flashes. The memory riser card diagnostic 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. 
						

							Mac Pro (8x) Troubleshooting — General Information 13 9
Diagnostic LEDs
The Mac Pro (8x) logic board includes a set of LEDs to help service providers troubleshoot the 
computer. The LEDs are located toward the rear of the logic board, under the memory cage, next 
to PCI card slot 1. You can view these LEDs by removing the computer’s side access panel and 
looking through the memory cage to the logic board below. LEDs 2, 3, 4, and 5 are normally off 
and will automatically illuminate if an error occurs. To read LEDs 1, 6, 7, and 8, you must press the  
DIAG_LED button, which is adjacent to the LEDs. To press the DIAG_LED button, use the nylon 
probe tool (Apple part number 922-5065). 
						

							Mac Pro (8x) Troubleshooting — General Information 140
Use the following table to interpret the LEDs.
LocationNameColorNominalPress DIAG_
LED button 
to display
Indicates
Led 1Trickle PwrYellowOnYe sPower supply 
is providing 
trickle power
Led 2CPU B ErrorRedOffNoCPU B halts 
on an IERR 
(instruction 
error)
Led 3CPU A ErrorRedOffNoCPU A halts 
on an IERR 
(instruction 
error)
Led 4CPU B OTRedOffNoCPU B is over 
temperature
Led 5CPU A OTRedOffNoCPU A is over 
temperature
Led 6GPU PresentGreenOnYe sEFI has 
configured 
the graphics 
card
Led 7Power OnGreenOnYe sAll power 
rails are 
functioning
Led 8EFI DoneGreenOnYe sEFI is done 
loading
Note: There is a position on the logic board next to LED 1 for a SLEEP LED that does not have any 
LED installed. This is normal; the LED was used only in development. To determine if a Mac Pro 
(8x) computer is in sleep mode, watch the power LED on the front of the computer. It will slowly 
change brightness levels if the computer is sleeping.
LED 1 Trickle Power
Normally on when DIAG_LED button is pressed. 
If LED 1 is not on, the symptom would be that the computer won’t power on. 
Troubleshooting: 
Check AC cord is connected to a working AC wall outlet. • 
Reseat AC Plug.• 
Check connections of power supply cables to the logic board. • 
Check power supply cable connections at power supply. • 
Replace power supply.•