Service Source Power Mac G5 Updated: 16 September 2003 © 2003 Apple Computer, Inc. All rights reserved.
Power Mac G5 Power Mac G4 - 1
Service Source Basics Power Mac G5 © 2003 Apple Computer, Inc. All rights reserved.
Overview Power Mac G5 is a 64-bit desktop computer powered by the PowerPC G5 processor. It offers memory expansion up to 8GB,1 GHz front-side bus, and advanced 64-bit computation, while running existing 32-bit applications natively. The computer also includes serial ATA hard drives, high-end graphics capabilities, and computer-controlled cooling based on four independent zones. Standard configurations are listed below. 1.6 GHz Uni Overview 1.
Serial Number Location To identify a particular model of Power Mac G5, check the computer’s serial number, which lists the model’s configuration. The serial number is located directly below the air deflector inside the side access panel.
What’s New Overview PowerPC G5— The Power Mac G5 computer incudes the new 64-bit PowerPC G5 processor running at either 1.6, 1.8, or 2.0 GHz, well beyond the speeds of G4 processors. Serial ATA hard drives — Unlike older parallel drives, the new serial ATA drives in the Power Mac G5 offer up to 150 MB/s data throughput. The 7200 rpm drives come in 80, 160, or 250 GB capacity. PCI-X slots—Higher-bandwidth PCI slots allow for greater amounts of data when using expansion cards that demand high performance.
DDR Memory Depending on the model, Power Mac G5 computers have either four or eight Dual Inline Memory Module (DIMM) slots for Double-Data-Rate (DDR) Synchronous Dynamic Random-Access Memory (SDRAM) devices. The computers ship with a minimum of 256 MB of RAM, installed as a pair of 128 MB DIMMs in two of the DIMM slots. You can install additional DIMMs, provided they are installed in pairs of equal size. A diagram marked on the logic board near the slots illustrates how the pairs must be installed.
Video The Power Mac G5 computer comes with a graphics card installed in the AGP 3.0compliant 8x Pro slot. All graphics cards support dual displays in either extended desktop or video mirroring mode, and support digital resolutions up to 1920x1200 pixels and analog resolutions up to 1600x1200 pixels. The display memory on the AGP card is separate from the main memory. The display memory consists of 64 or 128 MB of DDR devices configured to make a 128-bit data bus.
Analog audio signals are converted to digital data internally. All audio is handled digitally inside the computer, including audio data from the CD or DVD drive and from devices connected to the USB and FireWire ports. Audio data is converted to analog form for output to the internal speaker, the headphones, or the analog output port.
What’s New Power Mac G5 Basics - 7
Service Source Take Apart Power Mac G5 © 2003 Apple Computer, Inc. All rights reserved.
General Information Orientation For most take-apart procedures, it is recommended that you lay the computer on its side before removing or installing the part. For proper operation, however, Apple recommends that the unit be run in the upright position. The computer should never be operated on its side with the access panel facing down.
Opening the Computer Tools No tools are required for this procedure. Preliminary Steps 1. Shut down the computer. Warning: Always shut down the computer before opening it to avoid damaging its internal components or the components you are installing. Do not open the computer or attempt to install items inside it while it is on. 2. Wait 5 to 10 minutes to allow the computer’s internal components to cool. Warning: After you shut down the system, the internal components can be very hot.
Procedure 1. Hold the side access panel and lift the latch on the back of the computer. Warning: The edges of the access panel and the enclosure can be sharp. Be very careful when handling them. 2. Remove the access panel and place it on a flat surface covered by a soft, clean cloth. Replacement Note: Make sure the latch is in the up position before replacing the access panel. If the latch is down, the access panel will not seat correctly in the enclosure.
3. Remove the air deflector and place it on a soft, clean cloth. Replacement Note: To replace the air deflector, insert the three tabs on the bottom edge of the deflector into the three slots in the bottom frame of the enclosure. Then swing the deflector up flush against the top frame of the enclosure. Important: Make sure you re-install the air deflector before replacing the access panel. If the air deflector is not installed, the computer will not function properly.
Serial ATA Hard Drive The Power Mac G5 computer can accommodate two serial ATA hard drives in its internal hard drive bay. In most configurations, a single hard drive occupies the top portion of the bay. You can install one additional serial ATA hard drive to the empty slot in the bay. Important: Use the original Apple cables that came with the Power Mac G5 when installing ATA hard drives. Tools The only tool required for this procedure is a Phillips screwdriver.
Procedure 1. Release the drive locking latch by rotating it up. 2. Disconnect the drive data cable and power cable from the hard drive. 3. Pull the drive out of the drive bay, being careful not to touch the bottom of the drive. Important: If the printed circuit board (PCB) is exposed on the bottom of the hard drive, hold the drive by its sides. To avoid damaging the replacement drive, take care not to touch the PCB during installation.
4. If you are replacing the drive with a new drive, transfer the four hard drive guide screws from the sides of the original drive to the replacement drive. 5. If you are installing an additional drive, remove the four guide screws from the left side of the hard drive bay and screw them into the sides of the new drive.
Replacement Note: When replacing the top drive, make sure the guide screws align with the middle slot of the drive bay, and then gently push the drive into the bay until it snaps into place in the top position. When installing a bottom drive, align the guide screws with the bottom slot of the drive bay and slide the drive in until it snaps into place.
Optical Drive Important: When installing a replacement optical drive, use the original Apple cables that came with the Power Mac G5. Tools No tools are required for this procedure. Preliminary Steps Before you begin, open the computer.
Procedure 1. Disconnect the optical drive ribbon cable from the logic board. (The cable connector is located under the media shelf that holds the optical drive.) 2. Push the optical drive levers out to release the drive.
3. Place the fingers on one hand inside the opening for the optical drive cable and push the edge of the drive forward. The drive will move part way out of the media shelf. 4. Disconnect the power cable from the drive. 5. Route the drive ribbon cable out through the opening in the media shelf and remove the drive and ribbon cable from the computer.
6. If you are replacing the drive with a new drive, install the standoffs on the bottom of the new drive. Note for SuperDrives: Two bags of standoffs are included with each drive. Use the standoffs from the bag marked with the same manufacturer’s name as printed on the drive. Note for Combo Drives: Transfer the standoffs from the original drive to the replacement drive.
7. Disconnect the ribbon cable from the back of the drive, and then carefully pry the cable from the top of the drive. Transfer the cable to the top of the replacement drive, and connect the cable to the drive. Note: Reusable adhesive tape on the underside of the cable attaches the cable to the drive. When removing the cable from the original drive, be careful to keep the tape with the cable. 8.
Front Inlet Fan(s) The front inlet fan assembly consists of one or two fans in a plastic bracket. If the computer is a uniprocessor, the assembly contains a single fan; if the computer is a dual processor, the assembly contains two fans connected by a single cable. You must remove the front inlet fan assembly to access many other parts within the computer. For this access, remove the bracket with the fans attached.
Procedure 1. Hold the front inlet fan assembly by the front handle and firmly pull it out of the computer.
2. If you are replacing the fan(s) in the bracket, do the following: • Remove the fan cable from the cable guide. • Using needlenose pliers, pull the fan(s) off the grommet fasteners, and remove the fan(s) and cable from the bracket. Important: If you are replacing two fans, be careful that you do not separate the fans from each other. They are connected by a common cable.
Replacement Note: To replace the front inlet fan bracket in the enclosure, align the large rail on the bracket with the cutout in the PCI divider and press firmly. Important: Make sure the connector on the fan fully engages the fan connector on the logic board, or the computer will not operate properly. Gently pull the fan assembly to test whether it is connected.
Memory (DIMMs) Depending on the model, Power Mac G5 computers have either four or eight Dual Inline Memory Module (DIMM) slots arranged in two banks. The slots accept Double-Data-Rate (DDR) Synchronous Dynamic Random-Access Memory (SDRAM) devices. The computers ship with a minimum of 256 MB of RAM, provided by a pair of 128 MB DIMMs installed in slot 1 of each DIMM bank. You can add DIMMs, provided they are installed in pairs of equal size, one per bank, from the center outward.
In addition, DIMMs must fit these specifications: • 2.5 volt • 84-pin module • Maximum number of memory devices on DDR SDRAM:16. • Nonparity • No error correcting codes (ECC) • Unbuffered (registered or buffered DDR SDRAM cannot be used) Important: Always install DIMMs in pairs of equal size. Memory from older Macintosh computers is not compatible with the Power Mac G5. Do not use older memory, even if it fits into the DIMM slots. Tools No tools are required for this procedure.
Procedure 1. Locate the DIMM slots on the logic board. 2. Open the ejectors on the DIMM slot by pushing them out to the sides. 3. Holding the DIMM by both top corners, lift it straight up out of the computer. Replacement Note: Align the DIMM in the slot and push both ends of the DIMM down until the tabs are vertical and the ejectors snap into place. Important: Do not touch the DIMM connectors. Handle the DIMM only by the edges.
AGP/PCI Card The Power Mac G5 computer has four expansion card slots, three of which accommodate Peripheral Component Interconnect (PCI) cards and one that accepts an advanced graphics port (AGP) video card. AGP cards and PCI cards have different connectors, so you cannot insert a PCI card into the AGP slot. Note: Maximum power consumption for all four expansion slots (the three PCI expansion cards and the AGP card) should not exceed 90 watts (W).
MHz PCI slots and cannot use PCI-X cards; computers with eight DIMM slots can accommodate 100 and 133 MHz PCI-X cards. See the chart below. Card type PCI slot Card speed PCI* slots 2, 3, and 4 64-bit, 33 MHz PCI-X slots 2 and 3 slot 4 64-bit, 100 MHz 64-bit, 133 MHz *The PCI slots can accommodate mixed-voltage (5.0 V, 12 V, or 3.3 V) cards but only at 3.3 V signaling, with 32-bit or 64-bit data widths and a 33 MHz frequency.
Procedure Install an AGP video card in slot 1 only. Install either PCI or PCI-X cards in the slots labeled 2, 3, and 4. Warning: When removing or installing a PCI or AGP card, handle it only by the edges. Do not touch its connectors or any of the components on the card. Lift the card straight out from the connector to remove it, and insert it straight into the connector to install it. Do not rock the card from side to side and don’t force the card into the slot.
AirPort Extreme Card Only the AirPort Extreme Card may be installed in the Power Mac G5. Older AirPort Cards do not work in this computer. Tools No tools are required for this procedure. Preliminary Steps Before you begin, open the computer and lay it on its side with the access side facing up.
Procedure 1. Carefully disconnect the antenna cable from the end of the AirPort Extreme Card. 2. Pull the card straight back out of the enclosure. Replacement Note: Position the AirPort Extreme Card with the ID numbers and barcode facing up and insert the card into the AirPort Extreme Card connector. Important: Be sure to reconnect the antenna cable to the card.
Battery Tools No tools are required for this procedure. You may, however, find a flat-blade screwdriver useful in removing the battery from its holder. Preliminary Steps Before you begin, open the computer and lay it on its side with the access side facing up. If a PCI card is installed in the slot next to the battery, remove the card.
Procedure 1. If necessary, carefully spread the tabs holding the battery. 2. Remove the battery from its holder, noting the orientation of the battery’s positive end. (A plus sign is marked on or near the battery holder.) Replacement Note: Insert the new battery in the holder, making sure the battery’s positive symbol aligns with the positive symbol on or near the holder. Warning: Installing the battery incorrectly may cause an explosion.
Rear Exhaust Fan(s) Tools The following tools required for this procedure: • Phillips screwdriver • Needlenose pliers • Flatblade screwdriver Preliminary Steps Before you begin, open the computer, lay it on its side with the access side facing up, and remove all AGP and PCI cards.
Procedure 1. Disconnect the fan cable from the logic board. Note: Press the cable connector up toward the media shelf when disconnecting the cable. 2. Press down on the two tabs on the top of the fan bracket to release the two latches. 3. Lift the fan bracket and fans out of the enclosure.
4. If you are replacing the fans, use needlenose pliers to pull each fan off the four grommets that mount it to the bracket, and remove the fans and cable from the bracket. Replacement Note: When reinstalling the fan bracket in the enclosure, make sure the two tabs on the bottom of the bracket engage with the slots in the enclosure’s fan guide.
Then rotate the fan back flush with the rear panel, making sure the two latches on the top of the bracket engage with the two slots on the top of the fan guide. Replacement Note: Using a flatblade screwdriver, tuck the fan cable under the edge of the logic board.
Speaker/Fan Assembly Tools The only tools required for this procedure are a Phillips screwdriver and needlenose pliers. Preliminary Steps Before you begin, open the computer and lay it on its side with the access side facing up.
Procedure 1. Disconnect the speaker and fan cables from the logic board. 2. Lift the speaker/fan assembly straight up and remove it from the enclosure. Important: Be careful that the fan and speaker cables do not catch on the PCI divider as you lift the assembly. 3. If you are replacing the speaker, remove the two screws and remove the speaker from the speaker/fan bracket.
4. If you are replacing the fan, use needlenose pliers to pull the fan off the four grommet fasteners. Then remove the fan from the bracket. Replacement Note: When reinstalling the speaker/fan bracket in the enclosure, make sure the large tab on the side of bracket engages with the channel in the PCI divider.
Modem Board 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 speaker/fan assembly.
Procedure 1. Remove the two screws that secure the modem board. 2. Lift the board slightly and disconnect the modem filter cable from the modem board. 3. Remove the modem from the enclosure. Important: Be sure to reconnect the modem filter cable before reinstalling the modem.
Bluetooth Card 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 speaker/fan assembly.
Procedure 1. Remove the two Bluetooth mouning screws. 2. Lift the Bluetooth card straight up a short distance to disconnect it from the logic board. Then turn the card over, and disconnect the Bluetooth antenna cable from the underside of the card. Replacement Note: Be very careful connecting the antenna cable to the Bluetooth card. The connector is fragile and can easily be bent.
Processor Tools The only tool required for this procedure is a long-handled Phillips screwdriver. Preliminary Steps Before you begin, open the computer, lay it on its side with the access side facing up, and remove the front inlet fan assembly.
Procedure 1. Remove the metal G5 cap from the top of the heatsink. Note: The cap is held in place by two sets of small plastic latches on the underside of the cap. To release the latches, place both index fingers under the edge of the cap near the “G” and press in on the first set of latches. Then release the second set of latches under the opposite edge of the cap and lift the cap off the heatsink.
2. Using a long-handled Phillips screwdriver, remove the four processor mounting screws. 3. Lift the heatsink and processor straight up out of the computer. Warning: The heatsink and processor are a unit. Never separate the heatsink from the processor, or you will damage the processor and void the warranty. 4. Repeat steps 1–3 for the second processor, if necessary.
Replacement Note: If you are replacing the processor with a new processor, do the following: • When removing the new processor from its packaging, be careful to lift the processor straight up out of the box. Tilting the processor could damage the heatsink seal. • Before installing the processor, remove the cap over the processor connector. Warning: Do not remove the clear plastic strip on the bottom of the processor. Removing the plastic could cause a short in the logic board.
Modem Filter Board and Cables Tools The only tool required for this procedure is a Phillips screwdriver.
Procedure 1. Route the modem filter board cable out through the opening in the PCI divider. 2. Disengage the cable from the cable guides on the PCI divider. 3. Disconnect the power cable next to the modem filter board. 4. Remove the mounting screw on the modem filter board cap.
5. Slide the modem filter board back to disengage it from its mounting bracket, and remove the board and cable from the logic board. Replacement Note: When re-installing the modem filter board in its mounting bracket, be careful to engage the slots in the board with the edges of the bracket.
Replacement Note: Make sure the modem filter cable routes out through the opening in the side of the modem filter cap before securing the cap to the modem filter board. Replacement Note: Be careful when rerouting the modem filter cable that it routes under the black connector for the front inlet fan and out through the correct opening in the PCI divider. Make sure the cable is in place behind all cable guides.
Antenna Board and Cables Tools The only tool required for this procedure is a Phillips screwdriver.
Procedure 1. Disconnect the black antenna cable from the AirPort Extreme Card (if installed). 2. Disconnect the gray antenna cable from the Bluetooth card (if installed). 3. Bend the antenna board shield back far enough so that you can access the two antenna board mounting screws, and remove the screws.
4. Remove the Bluetooth cable (gray) and AirPort cable (black) from the cable guides and remove the antenna board and cables from the logic board. Replacement Note: Be careful when rerouting the two antenna cables that they route under the black connector for the front inlet fan. Make sure that the cables are in place behind all cable guides.
Front Panel Board Cable Tools No tools are required for this procedure. Preliminary Steps Before you begin, open the computer and lay it on its side with the access side facing up.
Procedure 1. Remove the two black plastic caps that cover the front panel board cable connectors. Note: The caps fit tightly over the connectors. To remove them, rock the caps gently forward and backward as you lift up. 2. Disconnect the cable from the logic board. 3. Disconnect the other end of the cable from the front panel board and remove the cable from the enclosure.
PCI Card Guide Tools The only tool required for this procedure is a Phillips screwdriver. Preliminary Steps Before you begin, open the computer and lay it on its side with the access side facing up.
Procedure 1. Remove the two screws that mount the PCI card guide to the logic board. 2. Slide the card guide up to release the two latches from the PCI divider, and remove the card guide from the enclosure.
Power Supply Tools The only tool required for this procedure is a short-handled Phillips screwdriver.
Procedure 1. Remove the black plastic caps covering the two power supply cable connectors. Note: The caps fit tightly over the connectors. To remove them, rock the caps gently forward and backward as you lift up. 2. Press in on the release latch on the first power supply cable connector and disconnect the cable from the logic board. Repeat for the other power supply cable. 3. Remove the two screws that secure the power supply top cover, and remove the cover from the enclosure.
4. Remove the four power supply mounting screws on the bottom of the enclosure. 5. Push in on the power receptacle, and slide the power supply toward the front of the computer. 6. Tilt the power supply a short distance out of the bottom of the enclosure.
7. Disconnect the power harness cable from the power supply. 8. Remove the power supply from the enclosure. Replacement Note: After reconnecting the power supply to the power harness cable, slightly lift the cable so that it does not become wedged under the power supply, and lower the power supply into the enclosure. Rotate the power supply back flush with the enclosure bottom until it snaps into place.
Logic Board Tools The only tools required for this procedure are a Phillips screwdriver and a hex wrench.
Procedure 1. Remove the two screws that secure the PCI card guide. 2. Disconnect the six cables from the top of the logic board. 3. Using a hex wrench, remove the four standoffs for the upper processor. Using a Phillips screwdriver, remove the remaining processor standoff (marked by a square in the illustration below). Repeat the procedure for a second processor, if installed. 4. Remove the five screws that secure the logic board.
5. Carefully 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. 6.
8. Disconnect the front inlet fan cable from the logic board. 9. Remove the three PCI divider mounting screws and remove the divider (with PCI card guide and thermistor attached) from the logic board. 10. Position the PCI divider on the replacement logic board and install the three mounting screws. 11. Connect the thermistor and front inlet fan cable to the logic board.
12. Install the modem filter board and cable on the logic board. 13. Install the antenna board and cables on the logic board. Note: Be careful when rerouting the two antenna cables and the modem filter cable that they route under the black connector for the front inlet fan. Make sure that the cables are in place behind all cable guides and that the modem filter cable routes out through the correct opening in the PCI divider. 14.
17. 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.
Replacement Procedure 1. Temporarily tape the top six cables to the media shelf so that they are out of the way. 2. Angle the logic board into the enclosure so that the port edge goes in first. 3. Position the logic board on the three guide pins, aligning the ports with the openings in the enclosure. 4. 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.
5. Replace the logic board screws and standoffs. 6. Replace the two PCI card guide screws. 7. Connect the six cables at the top of the logic board to the board. 8. Replace the power supply and reconnect all power supply cables to the logic board. 9. Replace the front panel board cable. 10. Replace the speaker/fan assembly and reconnect its cables to the logic board. 11. Replace the rear exhaust fan assembly and reconnect its cable to the logic board. 12. Replace all AGP and PCI cards. 13.
PCI Divider Tools The only tools required for this procedure are a Phillips screwdriver and hex wrench.
Procedure 1. Disconnect the front inlet fan cable from the logic board. 2. Remove the thermistor from the cable guide on the end of the PCI divider.
3. Remove the modem filter board cable, Bluetooth cable, and AirPort cable from the cable guides on the PCI divider. Replacement Note: Be careful when rerouting the two antenna cables that they route under the black connector for the front inlet fan. Make sure that the cables are in place behind all cable guides. 4. Turn the logic board over so that bottom of the board faces up. Remove the three screws that secure the PCI divider, and remove the divider from the logic board.
5. Compress the two latches on the sides of the front inlet fan cable connector, press the connector down through the opening in the PCI divider, and remove the cable from the divider.
Thermistor Cable Tools The only tools required for this procedure are a Phillips screwdriver and hex wrench.
Procedure 1. Disconnect the thermistor cable from the logic board. 2. Remove the thermistor cable from the guide on the PCI divider.
Front Inlet Fan Cable Tools The only tools required for this procedure are a Phillips screwdriver and hex wrench.
Procedure 1. Compress the two latches on the sides of the fan cable connector, and press the connector down through the opening in the PCI divider. 2. Remove the cable from the PCI divider.
Front Panel Board Tools The only tools required for this procedure are a jeweler’s flatblade screwdriver, Phillips screwdriver, and hex wrench.
Procedure 1. Using a jeweler’s flatblade screwdriver, pry up the metal cap covering the front panel board EMI shield. 2. Using a Phillips screwdriver, remove the two front panel board mounting screws.
3. Carefully pull the board a short distance out of its EMI shield, and disconnect the power button cable from the board. 4. Remove the board and shield from the enclosure. Replacement Procedure 1. If you are replacing the front panel board with a new front panel board, do the following: • Peel the backing off the mylar insulation for the EMI shield, and apply the mylar to the side of the shield, as shown.
• Peel the backing off the EMI shield gasket and apply the gasket to the bottom of the shield, making sure the openings in the gasket align with the shield openings. 2. Thread the power button cable through the opening in the EMI shield and connect the cable to the front panel board. 3. Insert the front panel board into the EMI shield, making sure the ports are fully seated in the openings in the shield. 4.
Service Source Troubleshooting Power Mac G5 © 2003 Apple Computer, Inc. All rights reserved.
General Information DDR Memory In the Power Mac G5, DIMMs must always be installed in pairs of equal size and speed. Use PC2700 DDR-SDRAM for 4-DIMM-slot computers and PC3200 DDR-SDRAM for 8-DIMM-slot computers. Memory from older Macintosh computers is not compatible. Do not try to install non-DDR memory as it will not physically fit in the DIMM slots and could damage the logic board.
PCI and AGP Cards The Power Mac G5 computer has four expansion card slots, three of which accommodate Peripheral Component Interconnect (PCI) cards and one that accepts an advanced graphics port (AGP) video card. AGP cards and PCI cards have different connectors, so you cannot insert a PCI card into the AGP slot. AGP Slot 1 PCI Slot 2 PCI Slot 3 PCI Slot 4 Note: Maximum power consumption for all four expansion slots (the three PCI expansion cards and the AGP card) should not exceed 90 watts (W).
*The PCI slots can accommodate mixed-voltage (5.0 V, 12 V, or 3.3 V) cards but only at 3.3 V signaling, with 32-bit or 64-bit data widths and a 33 MHz frequency. You can add a 66 MHz card to a 33 MHz PCI slot if the card can operate at the lower 33 MHz rate. Warning: Installing PCI cards that function only at 66 MHz could damage the computer. However, cards that run at both 66 MHz and 33 MHz may be installed. Check with the card’s manufacturer to see if a 66 MHz card also works at 33 MHz.
Block Diagram The architecture of the Power Mac G5 computer is based on the PowerPC G5 microprocessor and two custom ICs: the U3 memory controller/bus bridge and the K2 I/O controller. roc or od l bi roc or od l er G5 i r pr ess r bi i bi bi u er G5 i r pr ess r bi i bi u 1 buses Main logic board AG r sl .1 G ps sl s e r bus S . p r rear bps e r r ller a bus bri e S r ller S . p r rear bps S . pr bps bus 1 bi .
Resetting the PMU on the Logic Board The PMU (Power Management Unit) is a microcontroller chip that controls all power functions for this computer. The PMU is a computer within a computer. Its function is to: • tell the computer to turn on, turn off, sleep, wake, idle, etc. • manage system resets from various commands. • maintain parameter RAM (PRAM). • manage the real-time clock. Important: Be very careful when handling the logic board.
Pinouts Power Supply P1 Connector Pin # Signal Color Pin# Signal Color 1 +5Vstb Purple 13 GND Black 2 GND Black 14 Power ON Green 3 FANtach White/Yellow 15 GND Black 4 GND Black 16 Reserved 5 Reserved 17 GND Black 6 GND Black 18 RTNaud(GND) Black 7 +12Vaud (12V2) Yellow 19 GND Black 8 GND Black 20 +5V sense Red 9 +3.
Power Supply P2 Connector Pin# Signal Color Pin# Signal Color 1 +3.3V Orange 9 +5V Red 2 +3.3V Orange 10 +5V Red 3 +3.3V Orange 11 +5V Red 4 +3.
Front Inlet Fan Connector Pin# Signal 1 FAN CPU Cpu AF MOTOR 2 FAN CPU AF TACH 3 FAN GND 4 FAN 12V 5 FAN CPU BF MOTOR 6 FAN CPU BF TACK 7 TEMP SENSE D- 8 TEMP SENSE D+ 8 - Power Mac G5 Troubleshooting General Information
Front Panel Board Connector Pin# Signal 1 25V 2 V-GND 3 FW TPA Twisted Pair Shield 110 Ohm 4 FW TPA + Twisted Pair Shield 110 Ohm 5 CHASSIS GND FW 6 CHASSIS GND USB 7 FW TPB Twisted Pair Shield 100 Ohm 8 FW TPB+ Twisted Pair Shield 100 Ohm 9 USB PWR 10 USB GND 11 USB Twisted Pair Shield 60 Ohm 12 USB+ Twisted Pair Shield 60 Ohm 13 LED 14 PWR BTN 15 AUDIO SENSE 16 AUDIO COM Twisted TRI 17 AUDIO RIGHT Twisted TRI 18 AUDIO LEFT Twisted TRI General Information Ty
Optical and Serial ATA Hard Drive Cable Connectors Power Optical Pin# Color Pin# Color 1 BLK 4 BLK 2 BLK 3 BLK 3 BLK 1 BLK 4 SP1 (HD1) SP2 (HD2) Pin# Color Pin# Color BLK 2 BLK 2 BLK 5 BLK 3 BLK 3 BLK 6 BLK 1 BLK 1 BLK 7 BLK 4 BLK 4 BLK Media Bay Temperature Sensor Cable 7 Pin Connector Signal 5 Pin Connector 4 Pin Connector 1 3.3V 1 1 2 [ ]G B CLK 2 3 ] [G B DAT 2 4 GND 4 5 OVER TEMP 5 6 DOOR AJAR 1 3 7 3.
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.
No power (LED on/off, no fans, no boot tone, no video) 1. Check power supply cables 2. Check logic board power rails 3. Check processor connector 4. Check logic board tape for dual config 5. Replace power supply 6. Replace processor 7. Replace logic board No boot (LED on/off, fans spin, no boot tone, no video) 1. Replace memory 2. Replace logic board Memory (blinking LED, fans spin, no boot tone, no video) 1. Check memory config and replace DIMMs 2.
Optical drive 1. Replace optical drive cable 2. Replace optical drive 3. Replace logic board FireWire port (front panel A) 1. Replace front panel board cable 2. Replace front panel board 3. Replace logic board Firewire port (rear A<->B) Replace logic board Firewire port (rear B<->B) Replace logic board Internal speakers (left or right fails, boot tone) Replace logic board Internal speakers (high-pitch tone) 1. Replace power supply 2. Replace logic board USB 2.0 (front port) 1.
Modem 1. Replace modem 2. Replace modem filter board 3. Replace logic board AirPort 1. Replace AirPort Card 2. Replace antenna card 3. Replace logic board Bluetooth 1. Replace Bluetooth card 2. Replace antenna card 3. Replace logic board Audio IO (front line in <-> headphones) 1. Replace front panel board cable 2. Replace front panel board 3. Reposition logic board 4.
Symptom Charts Power Mac G5 Troubleshooting - 15
Service Source Views Power Mac G5 © 2003 Apple Computer, Inc. All rights reserved.
Exploded Views Exploded View 1 Video Card 661-2912, 661-2921, 661-2922 Fibre Channel Card 661-1763 Super Drive 661-2908 Combo Drive 661-2909 Serial ATA Hard Drive 80GB 661-2905 160GB 661-2906 250GB 661-2907 Optical Drive EMI Shield 922-6036 Speaker / Fan Bracket 922-6029 Rear Exhaust Fan Bracket 922-6033 Speaker 922-5959 Rear Exhaust Fans 076-1047 Enclosure 922-5952 Fan 076-1049 Inlet / Processor Fan, Dual 076-1046 Inlet Fan Bracket, Dual 922-6031 Inlet / Processor Fan, Uni 076-1048 Inlet Fan Bracket
Exploded View #2 DC Heatsink Cover 922-6025 G5 Heatsink Cap 922-6026 PCI Divider 922-6207 Processor, 1.6 GHz, Uni 661-2899 Processor, 1.8 GHz, Uni 661-2900 Processor, 2.
Internal Views Overview Optical Drive Top Hard Drive Bay Battery Bottom Hard Drive Bay AirPort Extreme Card Connector Slots 2—4: PCI or PCI-X Slots (Depending on model) yyyyyy yyyyyy DDR SDRAM Slots (Either 4 or 8 Slots, depending on model) Internal Views Slot 1: AGP 8X Pro Slot (Graphics card installed) Power Mac G5 Views - 3
Logic Board Optical Digital Audio In Optical Digital Audio Out Audio Line Out Audio Line In BlueTooth Antenna AirPort Antenna USB 2.0 Port USB 2.
External Views Front View Optical Drive Status Light f Headphone Jack ¤ Power Button FireWire 400 Port External Views USB 2.
Rear View Latch DVI Display Port AirPort Antenna Port Bluetooth Antenna Port Access Covers for PCI Expansion Slots ADC Display Port Optical Digital Audio Out Port Optical Digital Audio In Port USB 2.
