Apple power mac g5 early 2005 User Manual

							
126 Power Mac G5 Take Apart

Logic Board: Power Mac G5 
(June 2004/Early 2005) 
Note: Most Power Mac G5 (June 2004/Early 2005) computers route the antenna board cables 
and modem filter board cable on the underside of the logic board. However, some Power Mac 
G5 (June 2004 Dual 1.8 GHz) computers route the antenna board and modem filter board cables 
on the top of the logic board. If the Power Mac G5 (June 2004 Dual 1.8 GHz) logic board you are 
repairing routes the cables on the top of the board, see the previous procedure for “Logic Board: 
Power Mac G5.”
Tools
The only tools required for this procedure are a long-handled Phillips screwdriver, a short-
handled Phillips screwdriver, and a hex wrench.
Preliminary Steps
Before you begin, open the computer, lay it on its side with the access side facing up, and remove 
the following:
Front inlet fan assembly
Heatsink cover(s)
Processor(s) for Power Mac G5 without LCS Heatsink or
Processor for Power Mac G5 with LCS Heatsink
All AGP and PCI cards
Rear exhaust fan assembly
PCI card guide
Speaker/fan assembly
Front panel board cable
Memory DIMM if it is in slot next to the power supply cable
Power supply for Power Mac G5 without LCS Heatsink or
Power supply for Power Mac G5 with LCS Heatsink
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Power Mac G5 Take Apart 127
Part Location 
						

							
128 Power Mac G5 Take Apart

Procedure
Disconnect the cables from the top of the logic board.
Remove the 10 standoffs from the logic board (marked by a square in the illustration below).
Remove the five screws that secure the logic board (marked by a circle in the illustration 
below).
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Carefully slide the logic board to the left to unhook the tabs (marked by a triangle in the 
illustration above). Tilt the logic board up and maneuver it out of the enclosure, making sure 
the ports clear the enclosure openings. 
Note: Perform the following procedures only if you are replacing the logic board with a new 
logic board.
Transfer the following from the original logic board to the replacement board (see individual 
procedures in this chapter for detailed steps): 
•  Memory DIMMs
 
•  AirPort Extreme Card (if installed)
 
•  Bluetooth card (if installed)
 
•  Modem (if installed)
 
•  Ambient board (if installed)
Disconnect the cables from the logic board and from the tabs on the PCI divider.
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130 Power Mac G5 Take Apart

Turn the logic board over. Remove the three PCI divider mounting screws and remove the 
divider from the logic board.
Position the PCI divider on the replacement logic board and install the three mounting 
screws.
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Connect the cables to the logic board and clip the cables onto the PCI divider. If the 
Bluetooth and /or AirPort cards are not installed, clip the cables to the left side of the PCI 
divider as shown below.
Connect the modem filter cable to the modem and install the modem on the logic board.
Install the AirPort Extreme Card and Bluetooth card on the logic board and connect their 
cables to the cards.
Install the memory DIMMs on the logic board.
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132 Power Mac G5 Take Apart

Transfer the port EMI shield from the original logic board to the replacement logic board, 
making sure the shield is fully seated on the ports.
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Replacement Procedure
Important: Replacement logic boards may have a mylar sheet or Kapton tape installed in the 
area of the processor connectors. Do not remove the mylar or tape.
Temporarily tape the top six cables to the media shelf so that they are out of the way. 
Note: You may find a long strip of packing tape useful in securing the cables.
Replace the ambient board.
Angle the logic board into the enclosure so that the port edge goes in first.
Position the logic board on the three guide pins, aligning the ports with the openings in the 
enclosure. 
Slide the board toward the rear of the computer so that the logic board locks onto the guide 
pins and the ports are fully seated in the back panel openings. 
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134 Power Mac G5 Take Apart
Note: When installing the logic board into the computer, make sure the antenna board 
shield is not bent back away from the case. The shield should touch the case when the logic 
board is fully installed.
Replace the logic board screws and standoffs.
Replace the two PCI card guide screws.
Connect the six cables at the top of the logic board to the board.
Replace the power supply and reconnect all power supply cables to the logic board.
Replace the front panel board cable.
Replace the PCI card guide.
Replace the speaker/fan assembly and reconnect its cables to the logic board.
Replace the rear exhaust fan assembly and reconnect its cable to the logic board.
Replace all AGP and PCI cards.
Replace the processor.
Replace the heatsink cover.
Replace the front inlet fan assembly.
Important: Whenever you replace a logic board with a new logic board, you must run Apple 
Service Diagnostic (once the computer is reassembled). Apple Service Diagnostic for Power Mac 
G5 is available as a download from the Disc Images section of the Apple Service Source website. 
For more information, see “Thermal Calibration” in the Troubleshooting chapter.
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Power Mac G5 Take Apart 135

Modem Filter Board and Cables: 
Power Mac G5 (June 2004/ 
Early 2005)
Note: Some Power Mac G5 (June 2004 Dual 1.8 GHz) computers route the modem filter board 
cables on top of the logic board. Refer to the “Modem Filter Board and Cables: Power Mac G5” 
procedure earlier in this chapter.
Tools
The only tool required for this procedure is a Phillips screwdriver.
Preliminary Steps
Before you begin, open the computer, lay it on its side with the access side facing up, and remove 
the following:
Front inlet fan assembly
Heatsink cover(s)
Processor(s) for Power Mac G5 without LCS Heatsink or
Processor for Power Mac G5 with LCS Heatsink
All AGP and PCI cards
Rear exhaust fan assembly
PCI card guide
Speaker/fan assembly
Front panel board cable
Memory DIMM if it is in slot next to the power supply cable
Power supply for Power Mac G5 without LCS Heatsink or
Power supply for Power Mac G5 with LCS Heatsink
Logic Board
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