Apple mac pro early 2008 User Manual

							Mac Pro (Early 2008) Take Apart — Processor Heatsinks for 3.2 GHz Processors 81
Using a long-handled, magnetized 3 mm flathead hex screwdriver, loosen the four captive 5. 
mounting screws for the lower processor heatsink in the order indicated below. 
6. Carefully tilt the heatsink so that it clears the bottom lip of the enclosure and then lift the 
heatsink out of the computer.
IMPORTANT:
Remember that you 
cannot leave the 
heatsink separated 
from either the upper 
or lower processor for 
more than 30 minutes.. 
						

							Mac Pro (Early 2008) Take Apart — Processor Heatsinks for 3.2 GHz Processors 82
Visual Inspection of Heatsink Gasket
Before installing a new or existing heatsink, check that the gasket that surrounds the silver-
colored coating on the underside of the heatsink is in good condition, as illustrated 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. 
Replacement Instructions for Krytox Grease
The Mac Pro (Early 2008 Dual 3.2 GHz) computer uses Krytox grease to ensure a proper seal 
between the heatsink and processor. A bead of the grease rims the gasket on the underside of 
the heatsink and comes pre-applied on replacement heatsinks. 
Re-installing Existing Heatsinks/Processors
If you are re-installing existing heatsinks and processors, or transferring existing heatsinks and 
processors to a replacement logic board, in most cases you do not need to reapply Krytox grease.  
However, if additional grease must be added, do the following:
Order the Mac Pro Grease Kit (part number 076-1258).• 
Reassemble the unit while you wait for the kit to arrive.• 
Once you have the kit, remove the heatsink and/or processor from the enclosure.• 
Using first the lint-free cloth and then the alcohol wipe from the grease kit, carefully clean • 
off any residual grease from the underside of the heatsink and the top of the processor. (See 
“Installing New Heatsinks” below for more information.) Finish wiping the surfaces one 
more time with the cloth. 
						

							Mac Pro (Early 2008) Take Apart — Processor Heatsinks for 3.2 GHz Processors 83
Using the pre-measured syringe of Krytox grease from the kit, evenly apply a bead of grease • 
around the full perimeter of the heatsink gasket. Apply the full syringe of grease to the 
gasket. 
Warning: Do not apply more grease than recommended. The grease must not overflow the 
heatsink and come in contact with the processor connector.
Do not apply any grease to the processor.• 
Installing New Processors
Do not apply new grease to either the heatsink or the processor. 
Installing New Heatsinks
If you are installing a new heatsink, do not apply new grease to either the heatsink or processor, 
as the replacement heatsink comes with the full capacity of grease applied. 
Note: When installing a new heatsink, be sure to remove any residual grease from the top edges 
of the heatsink’s processor. To clean off the grease, do the following:
Remove the processor from its holder on the logic board. (See “• Processors, 3.2 GHz” in this 
chapter.)
Using first the lint-free cloth and then the alcohol wipe included with the replacement • 
heatsink, carefully clean off any grease from the top edges of the processor. Be very careful 
not to touch the silver-colored coating on the top of the processor and the gold pins on the 
bottom of the processor.
Use the cloth to carefully wipe the top edges of the processor one more time to clean off any • 
remaining grease. 
						

							Mac Pro (Early 2008) Take Apart — Processor Heatsinks for 3.2 GHz Processors 84
Replacement Instructions for Heatsink
Note: If you are re-installing an existing heatsink, go directly to step 1 below. If you are installing 
a replacement heatsink, first do the following:
Unpack the new heatsink according to the instructions included in the parts box.• 
• Remove the protective cap covering the underside of the heatsink and transfer it to the 
heatsink you are returning to Apple. 
Apply the top gasket included in the parts box to the top of the heatsink.• 
IMPORTANT:
If you are installing a 
new heatsink, do not 
remove it from its  
vacuum-packed bag 
until you are ready to  
install it. Be sure to  
follow all directions for 
unpacking the heatsink 
that are included in its 
packing box. 
						

							Mac Pro (Early 2008) Take Apart — Processor Heatsinks for 3.2 GHz Processors 85
If you are replacing the • lower processor heatsink with a new heatsink, install the bumper 
included in the parts box on the side of the heatsink.
Visually inspect the gasket on the underside of the heatsink. See “1. Visual Inspection of 
Heatsink Gasket” earlier in this procedure. 
Carefully align the posts on the lower heatsink with the mounting holes in the logic board, 2.  
and lower the heatsink onto the processor.
Lightly tighten the heatsink mounting screws in the order indicated below. 3. 
To secure the heatsink to the processor, again tighten the screws in the order indicated.4. 
Repeat steps 1–4 for the upper processor heatsink.5.  
						

							Mac Pro (Early 2008) Take Apart — Processor Heatsinks for 3.2 GHz Processors 86
Disposal Instructions
Place all disposable materials used in removing or replacing a processor heatsink or processor 
inside the resealable plastic bag included with the replacement module. (Disposable materials 
include such items as protective gloves, alcohol wipes, lint-free cleaning cloths, Krytox grease and 
syringe, suction pipette, and heatsink gasket.) Pack this bag along with the failed module in the 
box that the replacement module came in, and return the box to Apple. 
						

							Mac Pro (Early 2008) Take Apart — Processors, 2.8 and 3.0 GHz 87
Processors, 2.8 and 3.0 GHz
This procedure applies to 2.8 GHz and 3.0 GHz configurations of the Mac Pro (Early 2008). For the 
3.2 GHz configuration, see the procedure “Processors, 3.2 GHz.”
Note: The steps in this procedure illustrate how to remove the lower processor (CPU B). The 
instructions are the same for removing the upper processor (CPU A).
Important: Every time you remove a processor, you must replace the thermal grease on the 
processor heatsink. New grease and alcohol wipes for removing the previous grease are included 
with replacement processors. Instructions for applying the grease are included with the processor 
heatsinks procedure.
Tools
No tools are required for this procedure. However, you may find a flat-blade screwdriver helpful in 
releasing the processor holder latch.
Preliminary Steps
Before you begin, open the computer, lay it on its side with the access side facing up, and remove 
the following:
Hard drives and hard drive carriers in drive bays 1 and • 2
PCI Express card installed in slot • 1
Any 12-inch PCI Express card• s
Processor heatsink cove• r
Front fan assembl• y
Top and bottom memory card• s
Memory cage with rear fan• 
Processor heatsinks for 2.8 and 3.0 GHz Processor• s 
						

							Mac Pro (Early 2008) Take Apart — Processors, 2.8 and 3.0 GHz 88
Part Location
Procedure
Release the latch on the metal processor holder. 1. 
Note: You may want to use a flat-blade screwdriver to help release the latches.  
						

							Mac Pro (Early 2008) Take Apart — Processors, 2.8 and 3.0 GHz 89
Rotate the top of the holder to the open position. 2. 
Lift the processor out of the holder.3.  
						

							Mac Pro (Early 2008) Take Apart — Processors, 2.8 and 3.0 GHz 90
Important: When removing or installing a processor, always hold the processor by the edges. 
Be extremely careful not to touch the gold pins on the bottom of the processor, as this type of 
connector is very sensitive to contamination. Also be careful not to touch the gold pins in the 
processor socket on the logic board.
Note: You can identify the processor by the speed etched on the processor can, as illustrated 
below. You must clean off the thermal grease from installed processors to see the speed.
Replacement Note: Before installing a replacement processor, remove the protective cap 
covering the new processor’s connector.