Text preview for : pmg4mirror.pdf part of Apple Power Mac G4 MDD Service Manual for the Apple Power Mac G4 Mirrored Drive Doors computer. Usually not included in most eBay Apple Service CD collections, for some weird reason.
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Service Source
Power Mac G4 (Mirrored Drive Doors)
Updated September 13, 2002
© 2002 Apple Computer, Inc. All rights reserved.
Service Source
Take Apart
Power Mac G4 (Mirrored Drive Doors)
© 2002 Apple Computer, Inc. All rights reserved.
General Information
Overview
The identifying characteristics on the front of this Power Mac G4 (Mirrored Drive Doors) computer are its top speaker and mirrored optical drive bezel. Like the Power Mac G4 (QuickSilver and QuickSilver 2002) computers, this model also has a silver-colored case.
Tools
The following tools are required: · #2 Phillips screwdriver · #1 Phillips screwdriver · T-10 Torx driver or 2.5 mm Allen wrench · Small flat-blade screwdriver · Needlenose pliers Note: Magnetized tools are recommended to avoid dropping screws within the computer.
General Information
Power Mac G4 (Mirrored) Take Apart - 1
Note: To organize the screws your remove from the computer, use a tray with divided compartments (such as a plastic ice cube tray).
Serial Number Location
The computer's serial number is located on the back panel.
Before Opening the Computer
Warning: The power supply in this computer is a high-voltage component and should not be opened for any reason, even when the computer is off. Warning: After shutting down the computer, you must wait a few minutes before servicing it to allow internal components to cool. 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.
Electrostatic Discharge (ESD) Precautions
Follow these steps to avoid damage from ESD before working inside the computer. 1. Shut down the computer. 2. Wait a few minutes to allow the computer's internal components to cool. 3. Unplug all cables from the computer except the power cord. 4. Touch the metal PCI access covers on the back of the computer to discharge static electricity. 5. Unplug the power cord. 6. Lift the latch on the side of the computer. (If the latch will not lift, check that the security lock port and lockable cover latch in the back of the computer are not locked.) 7. Put on an ESD wrist strap. 8. To avoid static electricity building back up in your body, do not walk around the room until after you have finished working and closed the computer.
Operating the Computer
Warning: In this computer the lower fan is in direct line with the heatsink. However, when the computer is open and the side panel is set down, the fan and heatsink are no longer in contact. To avoid overheating and permanent damage, never turn on the computer unless all of its internal and external parts are in place and it is closed. Operating the computer when it is open or missing parts can damage the computer or cause injury. 2 - Power Mac G4 (Mirrored) Take Apart General Information
Opening the Computer
Tools
No tools are required for this procedure.
Preliminary Steps
No preliminary steps are required before you begin this procedure.
Procedure
1. Lift the latch to unlock the right side access panel.
2. Note: Gently lower the side panel onto a clean, ESD-safe mat to avoid scratching the case. Lower the side panel until it lies flat. Note: Release the latch before returning the side panel to its upright closed position.
Opening the Computer
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Top Handles
Tools
The only tool required for this procedure is a 2.5 mm Allen wrench.
Part Location
Preliminary Steps
There are no preliminary steps for this procedure.
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Top Handles
Procedure
1. Remove the two Allen screws that secure the handle you are replacing.
2. Lift the handle from the computer.
Replacement Note: When replacing a handle, make sure the inner prongs fit inside the raised points on the computer.
Top Handles
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Replacement Note: When replacing a handle, make sure you orient the handle so the three tiny bumps are near the lower edge of the handle.The handle won't fit properly if it is turned upside down. The top front and top rear handles are interchangeable.
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Top Handles
Top Panel
Tools
No tools are required for this procedure.
Part Location
Preliminary Steps
Before you begin, remove the handles from the top front and top rear of the computer.
Top Panel
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Procedure
1. Slide the top panel toward the front of the computer to unhook the six tabs. 2. Lift the top panel from the chassis.
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Top Panel
Speaker Grill
Tools
The only tool required for this procedure is a small flat-blade screwdriver.
Part Location
Preliminary Steps
There are no preliminary steps for this procedure.
Speaker Grill
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Procedure
1. Insert the tip of a screwdriver into one of the openings in the speaker grill. Warning: To prevent damage to the speaker, do not insert the screwdriver too far. 2. Pry out the speaker grill.
Replacement Note: Press the replacement speaker grill into the speaker opening.
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Speaker Grill
Lower Supports
Tools
The only tool required for this procedure is a 2.5 mm Allen wrench.
Part Location
Preliminary Steps
Before you begin, place the computer upside down on an ESD mat. Warning: When the computer is upside down or the lower supports are removed, the computer can be unstable.
Lower Supports
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Procedure
1. With the computer upside down, remove the two Allen screws securing the support to the computer.
2. Remove the support from the computer.
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Lower Supports
Lower Panel, Front
Tools
No tools are required for this procedure.
Part Location
Preliminary Steps
Before you begin, remove the lower front support. Warning: When the computer is upside down or the lower support is removed, the computer can be unstable.
Lower Panel, Front
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Procedure
1. Lift the lower front panel from the chassis. There are no screws holding this panel to the chassis; the front support holds it in place. 2. Important: Note the routing of the AirPort antenna cable. Carefully remove it from the notches in the lower front panel.
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Lower Panel, Front
Lower Panel, Rear
Tools
No tools are required for this procedure.
Part Location
Preliminary Steps
Before you begin, remove the lower rear support. Warning: When the computer is upside down or the lower support is removed, the computer can be unstable.
Lower Panel, Rear
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Procedure
Lift the lower rear panel from the chassis. There are no screws holding this panel to the chassis; the rear support holds it in place.
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Lower Panel, Rear
Rear Vented Panel
Tools
The following tools are required for this procedure: · 2.5 mm Allen wrench · Flat-blade screwdriver
Part Location
Preliminary Steps
Before you begin, remove the following: · Lower rear support · Lower rear panel · Top rear handle Warning: When the computer is upside down or the lower supports are removed, the computer can be unstable. Rear Vented Panel Power Mac G4 (Mirrored) Take Apart - 17
Procedure
1. With the computer positioned on its left side panel, remove the three Allen screws securing the rear vented panel to the computer.
2. Use a flat-blade screwdriver to pry out the tabs from the lower chassis.
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Rear Vented Panel
3. Grasp the rear vented panel on both sides of the lockable cover latch, and forcefully pull off the rear vented panel.
Rear Vented Panel
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Hard Drive Carrier, Back
Tools
The following tools are required for this procedure: · Magnetized #2 Phillips screwdriver. · Pliers
Part Location
Preliminary Steps
Before you begin, open the side access panel.
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Hard Drive Carrier, Back
Procedure
1. Using a Phillips screwdriver, remove the screw that attaches the carrier to the chassis. Note: On some production models, the screw is not present not required. 2. Pull the left side lever forward, and slide the carrier up to release the mounting pegs on the back of the carrier from the chassis.
Hard Drive Carrier, Back
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3. Rotate the carrier back from the chassis far enough to reach the drive cables. Disconnect the hard drive data and power cables (P2 and P3) from the hard drive(s). Note: You might need to use pliers to grasp and disconnect the power cable connector(s).
4. Remove the carrier and drive(s) from the computer. Replacement Note: Connect the cables to the drives before installing the carrier.
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Hard Drive Carrier, Back
Replacement Note: Be sure to align the mounting pegs on the back of the carrier with the notches in the chassis. Then press the carrier in and down until the pegs engage and the left side lever clicks into place.
Hard Drive Carrier, Back
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Hard Drive Carrier, Front
Tools
The only tool required for this procedure is a magnetized Phillips screwdriver.
Part Location
Preliminary Steps
Before you begin, open the side access panel.
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Hard Drive Carrier, Front
Procedure
1. Press down on the carrier's right side lever. 2. Holding the lever down, slide the carrier forward and out of the computer. Warning: Be careful not to scrape any cables when sliding the carrier forward.
Replacement Note: Align the center mounting peg on the top of the carrier with the center channel on the underside of the optical drive shelf. This center peg helps to guide the carrier. Then align the two remaining pegs, and slide the carrier in until the pegs engage and the right side lever clicks into place.
Hard Drive Carrier, Front
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Replacement Note: Before closing the side access panel, make sure the P4 and P5 power cable connectors are either attached to the hard drives or tucked inside the front hard drive carrier.
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Hard Drive Carrier, Front
Hard Drive
Tools
The only tool required for this procedure is a Phillips screwdriver.
Preliminary Steps
Before you begin, do the following: · Open the side access panel. · Remove the hard drive carrier.
Procedure
1. Remove the four mounting screws from the sides of the drive carrier. 2. Slide the drive forward out the front of the drive carrier.
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ATA 100 Hard Drive Cable
Tools
No tools are required for this procedure.
Preliminary Steps
Before you begin, do the following: · Open the side access panel. · Remove the back hard drive carrier.
Procedure
1. Open the cable clamp at the bottom of the chassis. 2. Disconnect the ATA 100 cable from the connector at J34 on the logic board.
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Optical Drive
Tools
The only tool required for this procedure is a Phillips screwdriver.
Part Location
Preliminary Steps
Before you begin, open the side access panel.
Optical Drive
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Procedure
1. Loosen the captive screw near the front panel board. 2. Remove the lower screw that secures the optical drive carrier to the chassis.
3. Slide the back panel off the carrier.
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Optical Drive
4. Slide the carrier back and rotate it so that you can reach the drive cables. 5. Disconnect the drive data and power cables (P6 and P7) from the back of the optical drive(s) and remove the carrier from the computer.
6. Remove the four mounting screws from the sides of the drive carrier. 7. Slide the drive forward out the front of the drive carrier.
Optical Drive
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Replacement Note: Before sliding the carrier back onto the optical drive shelf, make sure the power cable bundle at the side panel is routed in the recessed channel.
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Optical Drive
Replacement Note: When sliding the carrier back onto the optical drive shelf, make sure the latch on the underside of the carrier engages with the notch in the drive shelf.
Replacement Note: Before sliding the rear panel back onto the carrier, make sure the top lip of the panel engages with the top edge of the drive carrier. Warning: Be careful not to pinch the power cable between the panel and the carrier.
Optical Drive
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Optical Drive Cable
Tools
No tools are required for this procedure.
Preliminary Steps
Before you begin, do the following: · Open the side access panel. · Remove the front hard drive carrier. · Remove the optical drive carrier.
Procedure
1. Peel up the optical drive cable from the double-sided tape on the optical drive shelf.
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2. Open the two cable clamps at the bottom of the chassis.
3. Disconnect the cable from the logic board and free the cable from the opening in the optical drive shelf.
Optical Drive Cable
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Lower Fan
Tools
The only tool required for this procedure is a small flat-blade screwdriver.
Part Location
Preliminary Steps
Before you begin, do the following: · Open the side access panel. · Remove the optical drive carrier.
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Procedure
1. Disconnect the ribbon cable from the logic board and fold it back to expose the lower fan cable connector.
2. Using a small flat-blade screwdriver, gently lift up the locking tab on the lower fan cable and disconnect the cable from the logic board. Replacement Note: Route the fan cable under the ribbon cable and over the narrower flex cable, as shown.
Lower Fan
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3. Slide the fan straight up to disconnect it from the optical drive shelf, and remove the fan from the computer.
Replacement Note: Align the fan with the three latches in the drive shelf and slide straight down until you feel the fan lock into place.
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Lower Fan
Left Side Panel
Tools
The following tools are required for this procedure: · 2.5 mm Allen wrench · Needlenose pliers
Part Location
Preliminary Steps
Before you begin, open the computer and remove the optical drive carrier.
Left Side Panel
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Procedure
1. Remove the four 2.5 mm Allen screws on the side panel.
2. Using a needlenose pliers, squeeze the tabs (located beside the power supply cable bundle) to release the left side panel from the metal chassis. 3. Lift the left side panel from the chassis.
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Left Side Panel
Front Panel
Tools
No tools are required for this procedure.
Part Location
Before you begin, open the computer and remove the following. · Handle at the top front of the computer · Support at the lower front of the computer · Speaker grill (if present) · Optical drive carrier Warning: When the lower support is removed, the computer can be unstable.
Front Panel
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Procedure
1. Open the side access panel. Locate the four front panel tabs. 2. Carefully push the front panel tabs inward to release them from the chassis.
3. Pull the front panel off the chassis. 4. Press inward on the four tabs to remove the optical drive bezel from the front panel.
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Front Panel
Power Supply
Tools
The following tools are required for this procedure: · #2 Phillips screwdriver · T-10 Torx driver
Part Location
Preliminary Steps
Before you begin, do the following: · Open the side access panel. · Remove the optical drive carrier. · Remove the lower fan.
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Procedure
Warning: The power supply in this computer is a high-voltage component and should not be opened for any reason, even when the computer is off. 1. Use a T-10 Torx driver to remove the power supply screw from the back panel.
2. Remove the Phillips screw from the side panel.
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Power Supply
3. Disconnect the power supply cables from all drives and from the logic board. 4. Release the power cable harness from the guides and route the harness out through the opening in the optical drive shelf.
Power Supply
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5. Slide the power supply forward and remove the power supply and cable harness from the computer.
Replacement Note: When rerouting the cable harness, make sure · connectors P4 and P5 are routed inside the front drive carrier · connectors P2 and P3 are routed so they can reach drives in the back drive carrier
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Power Supply
Speaker
Tools
The following tools are required for this procedure: · #2 Phillips screwdriver. · Small flat-blade screwdriver
Part Location
Preliminary Steps
Before you begin, do the following: · Open the side access panel. · Remove the optical drive carrier.
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Procedure
1. Using a small flat-blade screwdriver, lift up the locking tab on the speaker cable connector and disconnect the cable from the logic board. 2. Remove the cable from the cable guide.
3. Route the cable up and out through the opening in the optical drive shelf and out from under the speaker case.
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Speaker
4. Remove the speaker mounting screw.
5. Swing the speaker away from the chassis. Press in on the two latches on the right side of the speaker and release the speaker from the chassis.
6. Remove the speaker and cable from the computer.
Speaker
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Replacement Note: With the replacement speaker attached to the chassis, make sure to route the speaker cable through the chassis guides, as shown.
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Speaker
Optical Drive Bezel
Tools
No tools are required for this procedure.
Part Location
Preliminary Steps
Before you begin, do the following: · Open the side access panel. · Remove the optical drive carrier.
Optical Drive Bezel
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Procedure
1. Press in and release the top two latches on the inside of the optical drive bezel. 2. Press in and release the bottom two latches.
3. Remove the bezel from the computer.
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Optical Drive Bezel
Front Panel Board
Tools
The following tools are required for this procedure: · #2 Phillips screwdriver · Small flat-blade screwdriver · Needlenose pliers
Part Location
Preliminary Steps
Before you begin, do the following: · Open the side access panel. · Remove the optical drive carrier. · Remove the optical drive bezel.
Front Panel Board
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Procedure
1. Disconnect the front panel board cable from the front panel board. 2. Using a small flat-blade screwdriver, pry up the two black plastic pegs and then the two black plastic peg holders from the top of the front panel board.
3. Using a #2 Phillips screwdriver, remove the front panel board mounting screw.
4. Remove the front panel board through the front opening in the computer.
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Front Panel Board
Replacement Note: When replacing the black plastic peg holders, use needlenose pliers to compress the holders so they will fit into the holes in the top of the front panel board.
Front Panel Board
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Front Panel Board Cable
Tools
No tools are required for this procedure.
Part Location
Preliminary Steps
Before you begin, do the following: · Open the side access panel. · Remove the front hard drive carrier. · Remove the optical drive carrier. · Loosen the speaker cable.
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Procedure
1. Disconnect the front panel board cable from the front panel board.
2. Peel the front panel board cable from the recessed channel in the side chassis and route the cable through the opening in the optical drive shelf.
Front Panel Board Cable
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3. Open the two cable clamps at the bottom of the chassis and disconnect the front panel board connector from the logic board.
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Front Panel Board Cable
Optical Fan
Tools
The following tools are required for this procedure: · #2 Phillips screwdriver · Small flat-blade screwdriver
Part Location
Preliminary Steps
Before you begin, open the side access panel.
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Procedure
1. Using a small flat-blade screwdriver, gently lift up the locking tab on the optical fan cable and disconnect the cable from the logic board. 2. Remove the two Phillips screws from the fan baffle.
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Optical Fan
3. Slide the fan baffle forward to clear the two pegs, and lift the fan baffle off of the fan.
4. Pull the fan straight up to remove it from the two pegs. Route the fan cable under the surrounding foam wall.
Replacement Note: If the foam wall is damaged, replace it by peeling off the old foam and cleaning the chassis surface with an alcohol wipe. Then apply the new foam wall to the chassis.
Optical Fan
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DIMMs
Tools
No tools are required for this procedure.
Part Location
Preliminary Steps
Before you begin, do the following: · Open the side access panel. · Remove the heatsink if the DIMM is in the slot nearest the heatsink.
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DIMMs
Procedure
1. Push down the ejectors on the DIMM slot. 2. Holding the DIMM by both top corners, lift it straight up out of the server. Warning: When removing or installing the DIMM, handle it only by the edges. Do not touch its connectors. Lift the DIMM straight up from the connector to remove it, and insert it straight down into the connector to install it. Do not rock the DIMM from side to side.
Replacement Note: The DIMM is designed to fit into the slot only one way. Be sure to align the notch in the DIMM with the small rib inside the slot.
DIMMs
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Modem
Tools
The only tool required for this procedure is a Phillips screwdriver.
Part Location
Preliminary Steps
Before you begin, open the side access panel.
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Modem
Procedure
1. Using a Phillips screwdriver, remove the modem's two mounting screws. 2. Lift the modem straight up a short distance to disconnect it from the logic board. 3. Disconnect the modem cable from the modem. 4. Remove the modem from the computer.
Modem
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AirPort Card
Tools
No tools are required for this procedure.
Part Location
Preliminary Steps
Before you begin, open the side access panel.
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AirPort Card
Procedure
1. Detach the coaxial antenna wire from the port on the end of the AirPort Card.
2. Pull the clear plastic tab on the AirPort Card to disconnect the card from the connector on the logic board.
AirPort Card
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Note: If you are not replacing the AirPort Card, stow the antenna wire on the side of the PCI card guide, being careful not to bend or crimp the wire tightly.
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AirPort Card
Video Card
Tools
The only tool required for this procedure is a Phillips screwdriver.
Part Location
Preliminary Steps
Before you begin, open the side access panel.
Video Card
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Procedure
1. Using a Phillips screwdriver, remove the video card mounting screw.
2. Gently hold back the clip on the video card connector to release the card. 3. Pull the card straight up, and remove it from the computer.
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Video Card
Replacement Note: Install an AGP card in slot 1 only. Install PCI cards in the slots labeled PCI 2, 3, 4, and 5. Warning: Cables with large connectors may interfere with the enclosure in the PCI slot numbered 5, making it difficult to close the door and potentially causing damage to the PCI card. If this is the case, rearrange the cards in the slots. You may also connect the cable after the enclosure door is shut, but be sure to remove the cable before opening the door again. If the PCI cards are connected to each other with cables or jumpers, take care when closing the door.
Video Card
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SCSI Card
Tools
The only tool required for this procedure is a Phillips screwdriver.
Part Location
Preliminary Steps
Before you begin, open the side access panel.
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SCSI Card
Procedure
1. Disconnect the SCSI cable from the SCSI card.
2. Remove the SCSI card mounting screw.
SCSI Card
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3. Lift up the SCSI card from the slot on the logic board.
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SCSI Card
SCSI Cable
Tools
The only tool required for this procedure is a Phillips screwdriver.
Part Location
Preliminary Steps
Before you begin, open the side access panel.
SCSI Cable
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Procedure
1. Disconnect the SCSI cable from the SCSI card.
2. Disconnect the SCSI cable from the hard drives at the front and back hard drive carriers. 3. Disconnect the SCSI cable from the SCSI terminator at the bottom of the chassis.
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SCSI Cable
Battery
Tools
No tools are required for this procedure.
Part Location
Preliminary Steps
Before you begin, do the following: · Open the side access panel. · Remove the video card if a full-length video card extends over the battery.
Battery
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Procedure
1. Note the orientation of the battery's positive (+) end. 2. Remove the battery from its holder. Note: You may first need to spread the two tabs on the holder slightly apart to release the battery.
Note: When replacing the battery, make sure the positive (+) end of the battery aligns with the + symbol on the battery holder.
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Battery
Heatsink
Tools
The following tools are required for this procedure: · #1 Phillips screwdriver · #2 Phillips screwdriver
Part Location
Preliminary Steps
Before you begin, open the side access panel.
Heatsink
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Procedure
1. Remove the five heatsink mounting screws: · small #1 Phillips screw at back panel shield · medium #2 Phillips screws at heatsink bracket · three large #2 Phillips screws at remaining corners of heatsink
2. Lift the heatsink straight up and remove it from the computer.
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Heatsink
Note: Whenever you remove the heatsink, you must clean the heatsink base and add new thermal grease to the chips on the processor, as follows: · Apply a 3-mm round dot of thermal glue on the center of both chips. · Use an alcohol pad to gently clean and dry the underside of the heatsink. · Ensure the heatsink is level as you CAREFULLY place it on the processor. · Install the five screws, loosely tightening each half way before fully tightening each screw.
Heatsink
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Processor
Tools
No tools are required for this procedure.
Part Location
Preliminary Steps
Before you begin, do the following: · Open the side access panel. · Remove the heatsink.
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Processor
Procedure
1. Grasp the processor by the edges and lift slightly to disconnect it from the logic board. 2. Slide the processor toward the back panel and then lift the processor up and out of the computer, being careful to clear the two mounting pegs.
Processor
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Processor Stiffener
Tools
No tools are required for this procedure.
Part Location
Preliminary Steps
Before you begin, do the following: · Open the side access panel. · Remove the heatsink. · Remove the processor.
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Processor Stiffener
Procedure
1. Lift the processor stiffener straight up off the two mounting pegs. 2. Remove the stiffener from the computer.
Processor Stiffener
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Logic Board
Tools
The only tool required for this procedure is a Phillips screwdriver.
Part Location
Preliminary Steps
Before you begin, open the computer and remove the following. · DIMMs · Video card · SCSI card (if present) · Modem (if present) · AirPort Card (if present) · Heatsink · Processor
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Logic Board
· Processor stiffener Note: The replacement logic board does not include the heatsink, processor, processor stiffener, memory DIMMs, modem, Airport Card, or PCI/AGP cards. You must transfer these modules from the original board to the new one.
Procedure
1. Disconnect all cables to the logic board 2. Remove the logic board mounting screw.
3. Slide the logic board toward the front of the computer to clear the chassis hooks. 4. Lift up the end of the logic board nearest the front of the computer and remove the logic board. Note: Be careful that the logic board ports clear the openings in the back panel.
Logic Board
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Note: After installing a replacement logic board, be sure to transfer the processor stiffener, processor, heatsink, DIMMs, and any other cards to the new board. You must also remove the battery insulator tab from the battery holder on the new board.
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Logic Board
I/O Panel
Tools
The following tools are required for this procedure: · 2.5 mm Allen wrench · Phillips screwdriver · Flat-blade screwdriver
Part Location
Preliminary Steps
Before you begin, open the computer and remove the following: · DIMMs · SCSI card (if present) · Video card · Modem (if present)
I/O Panel
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· · · · ·
AirPort Card (if present) Heatsink Processor Processor stiffener Logic board
Procedure
1. Remove the two Allen screws from the I/O panel.
2. Remove the Phillips screw securing the access cover to the rear chassis. Remove the access cover.
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I/O Panel
3. Use a flat-blade screwdriver to pry up the hooked tabs from the slots in the chassis. Pull that end of the I/O panel forward.
4. From inside the chassis, pry up the two tabs near the modem filter board.
I/O Panel
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5. Remove the I/O panel from the chassis. Replacement Note: Before installing the replacement I/O panel, insert the I/O port liner into the panel.
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I/O Panel
Right Side Access Panel
Tools
The following tools are required for this procedure: · 2.5 mm Allen wrench · Phillips screwdriver · Needlenose pliers
Part Location
Preliminary Steps
Before you begin, open the computer and remove the following: · DIMMs · SCSI card (if present) · Video card · Modem (if present)
Right Side Access Panel
Power Mac G4 (Mirrored) Take Apart - 93
· · · · ·
AirPort Card (if present) Heatsink Processor Processor stiffener Logic board
Procedure
1. Remove the four 2.5 mm Allen screws on the side panel.
94 - Power Mac G4 (Mirrored) Take Apart
Right Side Access Panel
2. Open the side access panel.
3. Remove the two Phillips screws attaching the right side panel to the metal chassis.
4. Using needlenose pliers, squeeze the plastic tabs (protruding through the chassis), to release the right side panel from the metal chassis.
Right Side Access Panel
Power Mac G4 (Mirrored) Take Apart - 95
5. Remove the right side panel from the chassis.
Replacement Note: When installing the replacement right side access panel, make sure the latch is closed, and the metal latch spring pin inside the chassis fits under the plastic latch tab, as shown.
96 - Power Mac G4 (Mirrored) Take Apart
Right Side Access Panel
Modem Filter Board
Tools
The only tool required for this procedure is a Phillips screwdriver.
Part Location
Preliminary Steps
Before you begin, open the computer and remove the following. · DIMMs · Video card · SCSI card (if present) · Modem (if present) · AirPort Card (if present) · Heatsink · Processor · Processor stiffener · Logic board
Modem Filter Board
Power Mac G4 (Mirrored) Take Apart - 97
Procedure
1. Remove the mounting screw that secures the modem filter board to the back chassis. 2. Free the modem filter board cable from the guides in the chassis.
3. Swing the modem filter board out of the opening in the back chassis. Replacement Note: Install the two tiny tabs on the replacement modem filter board into the tiny slots on the back chassis. Then swing the board into place before securing the screw.
98 - Power Mac G4 (Mirrored) Take Apart
Modem Filter Board
Service Source
Troubleshooting
Power Mac G4 (Mirrored Drive Doors)
© 2002 Apple Computer, Inc. All rights reserved.
General Information
What's New
Available Configurations
Bus Speed L3 cache Memory Processor Optical Drive Configuration 133 MHz Good 167 MHz Better 167 MHz Best
Dual 867 MHz Power PC G4
256 MB, DDR 266 MHz
1 MB per processor
256 MB, DDR 333 MHz
1 MB per processor
2 MB per processor
Combination (DVD-ROM/CDRW)
Dual 1 GHz Power PC G4
512 MB, DDR 333 MHz
SuperDrive (DVD-R/CD-RW)
Dual 1.25 GHz Power PC G4
SuperDrive (DVD-R/CD-RW)
Cable-Select Drives
Important: This computer works with ATA and ATAPI internal storage devices that are set for cable select mode. The cable select feature forces the device to set its ID as either master or slave based upon its position on the ATA/ATAPI cable. If the device is attached to the end of the cable, then the device identifies itself as a master. If the device is at the middle cable position, then it is a slave. Because cable select mode forces the drive to set its ID based upon its position on the cable, hard drives and optical drives are easily configured. Before you install an additional third-party ATA and ATAPI drive, check the documentation that came with the drive or with the manufacturer to make sure it is set for cable select mode. Important: Use the original Apple cables that came with this computer when you install additional drives. Some non-Apple cables may not correctly support cable select mode.
General Information
Power Mac G4 (Mirrored) Troubleshooting - 1
DDR Memory
The computer's logic board includes four memory slots, which accept double-data rate (DDR) SDRAM DIMMs. Memory can be expanded to a maximum of 2 gigabytes. DIMMs used in this computer must fit these specifications: · PC2100 SDRAM DDR266 DIMMs for 133 MHz systems · PC2700 SDRAM DDR333 DIMMs for 167 MHz systems Important: Make sure that the memory installed on the logic board is compatible with the system. If PC2100 (DDR266) memory is put into a system with a 167 MHz logic board, the system will not boot. A single tone will sound instead of the boot chime, and the front LED will flash. And if PC2700 (DDR333) memory is put into a system with a 133 MHz logic board, the system will behave as though DDR266 DIMMs were installed. · 128, 256, or 512 MB DIMMs 256 MB DIMMs must have 128 or 256 megabit (Mbit) technology devices; 512 MB DIMMs must have 256 Mbit devices 2.5 volt 64-bit wide, 184-pin module unbuffered (do not use registered or buffered DRAM) maximum height of 1.3 inches
· · · ·
Important: DIMMs from older Macintosh computers are not compatible with this computer. Do not use older DIMMs even if they fit into the DIMM slots.
Ports
The standard configuration includes the following ports on the back panel: one Ethernet port, two FireWire ports, two USB ports, an internal modem port (on some models), Apple speaker mini-jack, an audio line-in port, an audio line-out port, a security lock port, a DVI monitor port, and an ADC monitor port. There is also one headphone jack on the front of the computer. The computer can be used with DVI or ADC monitors. To connect the computer to a VGA monitor, use the DVI-to-VGA adapter that came with the computer. Note: For a diagram of the ports location, see "External Views" in the Views chapter.
PCI and AGP Cards
The AGP 4X card, installed in slot 1, contains the graphics processor unit (GPU) and provides the monitor ports. Slot 1 is designed specifically to accept AGP cards. This 66 MHz slot accommodates 1.5 V AGP cards. The standard configuration of the computer has four PCI expansion slots, labeled 2, 3, 4, and 5, which accept PCI cards up to 12 inches long. Some models come with a SCSI PCI
2 - Power Mac G4 (Mirrored) Troubleshooting
General Information
card installed in one of these slots. The PCI slots can accommodate mixed voltage (5.0 V, 12 V, or 3.3 V) cards with 32-bit or 64-bit data widths and a 33 MHz frequency. A 66-MHz card can be used in a PCI slot if the card can operate at the lower 33 MHz rate. Note: Maximum power consumption by the cards is · 30 W for the AGP card · 60 W for four PCI cards Warning: Cables with large connectors may interfere with the enclosure in the PCI slot numbered 5, making it difficult to close the door and potentially causing damage to the PCI card. If this is the case, rearrange the cards in the slots. You may also connect the cable after the enclosure door is shut, but be sure to remove the cable before opening the door again. If the PCI cards are connected to each other with cables or jumpers, be careful when closing the door.
Ventilation
Warning: To prevent the computer from overheating, do not block the ventilation openings in the back panel.
Hard Drives
In this computer, the thickness of the hard drives must not exceed one inch (2.5 cm). The computer can accommodate two internal Ultra ATA hard drives in each hard drive carrier, for a total of four drives. If the computer has one Ultra ATA drive installed, it sits in the rear drive carrier. A second drive can be installed in the rear carrier and two additional drives in the front carrier. Warning: Do not swap ATA cable locations. The hard drive cables must not be swapped between hard drive carrier locations: · 100 MHz ATA bus speed cable at rear carrier · 66 MHz ATA bus speed cable at front carrier Note: Before installing a third-party drive, check with the drive manufacturer or the manufacturer's Web site to determine if the drive is set for cable select mode. Before installation, set the drive to cable select if the manufacturer has not done so.
General Information
Power Mac G4 (Mirrored) Troubleshooting - 3
Block Diagram
Backside L3 Cache 2MB SRAM Backside L3 Cache 2MB SRAM (Dual)
4.1 u P-I3 1.2 Cache 256KB I2C ROM FireWire Rear of Enclosure 10/100/Gb BaseT PHY Phy Powered Whenever AC Power Available 100/200/400/800 Mbps PHY 125 MHz, 8bit Gigabit Ethernet FireWire 100/200/400 800 Mbps PCI Interface 33MHz, 64 bit MaxBus 133 MHz MaxBus/60x Bus Interface 133 MHz, 64 bit Main Memory 133 MHz, 64 bit PowerPC Apollo 1.2 Cache 256KB PowerPC Apollo (Dual)
CPU Module
12V Main Fan Controller I 2 C for Serial Presence Detect
RI-45 Port Power (25V, 15W) 1394a 1394a
Uni
4 DDR SDRAM DIMM Slots Up to 2048MB using Industry Standard 512MB DIMMs
ATA 100 AGP-4x Interface Interface 66/133/266 MHz 32 bit
1024kB ROM Contains: ·Open Firmware ·Hardware INIT ·POST
AGP-4 Bus (PCI 0) 66/133/266MHz, 32bit PCI Bus (PCI 1) 33 MHz 64bit PCI Bus (PCI 1) 33MHz 64 bit
USB
1.5V AGP Slot KeyLargo I/O Controller Interrupt Controller DAV Audio USB #1 USB #2 I 2S Audio Serial SPI 5V Tolerant 33MHz, 64bit PCI Slots PCMCIA E-IDE ATA(PI) Ultra DMA66 25V ADC Monitor Power and Control
Equalizer Rear Panel 1/8" Line In and L1 Line Out LC Connectors Front Panel HP 1/8" Headphone Jack and Mono Speaker Rear Panel Apple Pro Speakers II w Eq ROM AP Stereo Stereo Stereo Mono 5V Sleep Rear of Enclosure Comm Slot POTS Modem Codec Amplifiers To AGP Unused
Pwr Mgr99 ·Sleep ·Power On/Off ·Power LED ·I2C
AirPort Slot AirPort Module
Cable Selects Master/ Slave
SuperDrive DVD-R, CD-R or Combo DVD, CD-R
Stereo Serial ROM
RJ-11 5V 3.3V Sleep Sleep
4 - Power Mac G4 (Mirrored) Troubleshooting
General Information
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. The PMU is very sensitive and touching the circuitry on the logic board can cause the PMU to crash. If the PMU crashes and is not reset, the battery life goes from about five years to about two days. Note: For the location of the PMU reset button, see "Logic Board Diagram" in the Views chapter. Many system problems can be resolved by resetting the PMU chip. When you have a computer that fails to power up, follow this procedure before replacing any modules: 1. Disconnect the power cord and check the battery in the battery holder. The battery should read 3.3 to 3.7 volts. If the battery is bad, replace it, wait ten seconds, and then proceed to step 2. If the battery is good, go directly to step 2. 2. Press the PMU reset button once and then proceed to step 3. Do not press the PMU reset button a second time because it could crash the PMU chip. 3. Wait ten seconds before connecting the power cord and powering on the computer. If the computer does not power on, there is something else wrong with it; refer to the "System" section of "Symptom Charts" in this chapter. Note: The above procedure resets the computer's PRAM. After resetting the PMU, be sure to reset the time, date, and other system parameter settings.
General Information
Power Mac G4 (Mirrored) Troubleshooting - 5
Power Supply Verification
To power on, the computer's logic board requires a "trickle" power of +5V. If the system fails to power on, first reset the PMU. Then follow the procedure outlined below to determine whether the problem is related to the power supply. Note: To verify the power supply, you need a volt meter. When connecting the volt meter leads to specific pins, make sure the power supply remains securely plugged into its connector on the logic board. The following figure shows the pins and voltage on the computer's power supply connector. (The color noted represents the color of the wire attached to the pin.) Black GND Pin 12 Pin 24 +12V Yellow Pin 23 GND Black Pin 22 +12V Yellow Pin 21 +12V Yellow Pin 20 GND Black Pin 19 +3.3V Orange Pin 18 +3.3V Orange Pin 17 +3.3V Orange Pin 16 GND Black Pin 15 +5V Red
Green Power On Pin 11 Black GND Pin 9 Black GND Pin 7
Yellow +12V Pin 10 Blue -12V Pin 8
Orange +3.3V Pin 6 Black GND Pin 5 Red +5V Pin 4 Red +5V Pin 3
Purple +5V TRKL Standby Pin 1
Black GND Pin 2
Pin 14 +25V Standby White Pin 13 GND Black
1. Plug a known-good power cord into the computer. Do not turn on the computer. 2. Connect the black lead of the volt meter to pin 12 of the power supply connector; connect the red lead of the volt meter to pin 24. The volt meter should measure approximately +12V. If you do not get a reading of +12V, recheck the volt meter connections and measure the voltage again. If voltage is still not present, replace the power supply. If you do measure +12V on pin 24, the power supply is likely OK. Go to the next step for further verification. 3. Start up the computer by pressing the power button on the front panel. If the computer starts up normally, the power supply is OK. If the computer does not start up, go to the next step.
6 - Power Mac G4 (Mirrored) Troubleshooting
General Information
4. Check to see if the power supply fan is spinning. If the fan spins, the power supply is OK. If the fan does not spin, go to the next step. 5. Connect the black lead of the volt meter to pin 12 of the power supply connector; connect the red lead to pin 6. The volt meter should measure approximately +3.3V. If you do not get a reading of +3.3V, recheck the volt meter connections and measure the voltage again. If voltage is still not present, replace the power supply. If you do measure +3.3V on pin 6, the power supply is likely OK. Go to the next step for further verification. 6. Connect the black lead of the volt meter to pin 12 of the power supply connector; connect the red lead to pin 3. The volt meter should measure approximately +5V. If you do not get a reading of +5V, recheck the volt meter connections and measure the voltage again. If voltage is still not present, replace the power supply. If you do measure +5V on pin 3, the power supply is likely OK. Go to the next step for further verification. 7. Connect the black lead of the volt meter to pin 12 of the power supply connector; connect the red lead to pin 10. The volt meter should measure approximately +12V. If you do not get a reading of +12V, recheck the volt meter connections and measure the voltage again. If voltage is still not present, replace the power supply. If you do measure +12V on pin 10, the power supply is OK and the testing is complete. You have verified that the power supply is not the cause of the "no apparent power" symptom.
RAM and Processor Verification: Power-On Self Test
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, you will not hear a normal startup chime. Instead, the system will beep as explained below: · 1 beep: No RAM is installed or detected. · 2 beeps: Incompatible RAM types are installed. · 3 beeps: No RAM banks passed memory testing. · 4 beeps: No good boot images are detected in the boot ROM (and/or there is a bad sys config block). · 5 beeps: The processor is not usable.
General Information
Power Mac G4 (Mirrored) Troubleshooting - 7
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. 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
System is completely dead (no fan movement and power LED is not lit)
1. Verify the power outlet is good. 2. Replace the power cord. 3. Make sure the voltage switch on the back of the power supply is set to the correct voltage. 4. Reset the logic board. Refer to "Resetting the PMU on the Logic Board" in this chapter. 5. Check for trickle voltage on the power supply connector. Refer to "Power Supply Verification" in this chapter. If verification fails, replace the power supply. 6. Disconnect external devices, including the monitor, and start up the computer. 7. Remove internal cards and start up the computer. 8. Disconnect internal hard drives from the logic board and start up the computer. 9. Check the modem connector. If the connector has any bent pins, replace the logic board. 10. Replace the logic board.
8 - Power Mac G4 (Mirrored) Troubleshooting
Startup Symptom Charts
Memory error message appears on the screen
1. Reseat the DIMMs. 2. Verify that only the correct SDRAM DIMMs are installed. 3. Replace the DIMMs one at a time and test until all bad DIMMs are replaced with known-good modules.
Flashing question mark appears on the screen
1. Start up from the system restore CD and check to see if the hard drive shows up in the Disk Utility. If it does, go to step 2. If it does not, go to step 4. 2. Run Disk Utility. Update the driver and restart the computer. 3. Reinstall system software using the system restore CD that came with the computer. 4. If you are starting up in Mac OS 9, turn off your Mac OS 9 system extensions: · Start up the computer while holding down the Shift key. · If the computer is set to start up from another computer on your network, check that the Ethernet cables are firmly connected, then restart the computer. If the computer has trouble connecting to the network, check that the startup computer or server is not down. · If in Mac OS 9, remove any items from the Servers folder in the System Folder. If that does not work, of if you are starting up in Mac OS X, turn off the computer by holding down the power button. Then start up using the Software Install CD. · Insert the system software CD and start up while holding down the C key. (Make sure the Caps Lock key is not engaged.) · After the computer starts up, see the troubleshooting information in the onscreen help. Choose Mac Help from the Help menu. Look at the section on how to prevent and solve problems. You may need to check for extension conflicts or reinstall the computer's system software. 5. Reseat the hard drive data and power cables. 6. Replace the hard drive.
Computer begins to power up, the fan and hard drive are spinning, the power LED is lit, but there is no startup chime or video
1. Reset the logic board. Refer to "Resetting the PMU on the Logic Board" in this chapter. 2. Verify all PCI and AGP cards are seated properly. 3. Reseat the processor module. 4. Replace the processor module. 5. Replace the logic board.
Startup Symptom Charts
Power Mac G4 (Mirrored) Troubleshooting - 9
No image on screen
1. Make sure the display and computer are turned on. 2. Make sure the cables are connected properly to the computer and display. 3. If an ADC display is connected, check the ADC connectors on the video card and the cable for physical damage. If the video card connector looks fine, test for the symptom with a known-good display. 4. Make sure the computer is not in sleep. Press the power button or any key to see if the computer wakes. 5. Make sure the display brightness and contrast are set properly. 6. Reset the PRAM by restarting the computer while holding down the Command, Option, P, and R keys until you hear the startup sound a second time. Then start up using the Software Install CD.
System shuts down intermittently
1. Make sure the power cord is plugged in firmly. 2. Check the Energy Saver settings. 3. Check that the power source is turned on and the correct voltage is present. 4. Replace the power cord. 5. Make sure the air vents are clear. 6. Check that the fan cables are connected and the fans are operational. 7. Check that the heatsink is properly attached to the processor. 8. Reset the logic board. Refer to "Resetting the PMU on the Logic Board" in this chapter. 9. Replace the power supply. 10. Replace the logic board.
System shuts down almost immediately after startup
1. Reset the logic board. Refer to "Resetting the PMU on the Logic Board" in this chapter. 2. Disconnect the power cables to all hard drives and optical drives. Remove all cards and test power sequentially to troubleshoot cards and drives. 3. Check the modem connector. If the connector has any bent pins, replace the logic board. 4. Replace the processor module. 5. Replace the power supply. 6. Replace the logic board. 10 - Power Mac G4 (Mirrored) Troubleshooting Startup Symptom Charts
System shuts down when using multiple FireWire devices and an Apple ADC 17" CRT display is connected
The power requirements for multiple FireWire devices and the Apple ADC 17" CRT display may exceed the capacity of the power supply, causing it to shut the system down. To alleviate this problem, do the following: 1. Reduce the number of bus-powered FireWire devices 2. Use a power adapter with all FireWire devices 3. Reduce monitor power draw by reducing brightness or reducing the amount of white space (open text documents, for example).
System quits or stops responding intermittently
1. If the system quits or stops responding in a specific application, force the application that has frozen to quit: · In Mac OS X, choose Force Quit from the Apple menu and select the application. · In Mac OS 9, hold down the Esc, Option and Command keys and click Force Quit in the dialog box. Replace the application. Verify the application is compatible with the operating system. 2. For a suspected software problem, · Use Software Update to ensure that the computer has the latest drivers, bug fixes, and other updates. · For problems with software from a manufacturer other than Apple, contact the manufacturer. 3. Clear parameter RAM. Hold down Command-Option-P-R during startup until you hear a second startup chime. 4. Perform a clean install of system software with the system restore CD that came with the computer. 5. Run Disk Utility. 6. Replace the DIMMs one at a time and test until all bad DIMMs are replaced with known-good modules. 7. Reset the logic board. Refer to "Resetting the PMU on the Logic Board" in this chapter. 8. Replace the processor module. 9. Replace the logic board.
Startup Symptom Charts
Power Mac G4 (Mirrored) Troubleshooting - 11
Error Tones
Note: Error tones occur before system software loads.
Computer beeps once at startup
One beep means that no RAM is installed or detected. 1. If no DIMM is present, install a known-good DIMM in the top slot and try again. 2. Reseat the DIMMs. 3. Replace the DIMMs one at a time and test until all bad DIMMs are replaced with known-good modules. 4. Check that the processor module is properly installed. 5. Replace the processor module. 6. Replace the logic board.
Computer beeps two times at startup
Two beeps mean that incompatible RAM types may be installed. Verify that only DDR266 SDRAM DIMMs are installed. 1. Replace the DIMMs one at a time and test until all bad DIMMs are replaced with known-good modules. 2. Check that the processor module is properly installed. 3. Replace the processor module. 4. Replace the logic board.
Computer beeps three times at startup
Three beeps mean that no RAM banks passed memory testing. 1. Replace the DIMMs one at a time and test until all bad DIMMs are replaced with known-good modules. 2. Check that the processor module is properly installed. 3. Replace the processor module. 4. Replace the logic board.
Computer beeps four or five times at startup
Four or five beeps mean that the ROM is probably bad and cannot be fixed. 1. Replace the processor module. 2. Replace the logic board.
12 - Power Mac G4 (Mirrored) Troubleshooting
Error Tones Symptom Charts
Video
Screen is black, but startup chime is present, drive operates, fan is running, and power LED is lit
1. Check video cable/card connections and connector pins. 2. Test with a known-good monitor. Replace the monitor, if necessary. 3. Remove all third-party devices. 4. Reseat the video card. 5. Clear parameter RAM. Hold down Command-Option-P-R during startup until you hear a second startup chime. 6. Reset the logic board. Refer to "Resetting the PMU on the Logic Board" in this chapter. 7. Replace the video card. 8. Replace the logic board.
Screen is black, there is no startup chime, and drive does not operate, but fan is running and power LED is lit
1. Check video cable/card connections and connector pins. 2. Reset the logic board: 3. Refer to "Resetting the PMU on the Logic Board" in this chapter. 4. Reseat the video card. 5. Reseat the processor module. 6. Replace the processor module. 7. Replace the logic board.
Startup chime is present but screen is gray
1. Reset the logic board. Refer to "Resetting the PMU on the Logic Board" in this chapter. 2. Reseat all PCI cards. 3. Reseat all DIMMs. 4. Test with known-good DIMMs. 5. If using more than one display, make sure primary display is connected to video card. 6. Reseat the processor module. 7. Replace the processor module. 8. Replace the logic board.
Video Symptom Charts
Power Mac G4 (Mirrored) Troubleshooting - 13
Video is distorted
1. Make sure that the video card driver and firmware are updated to the most recent versions. 2. Refer to the adjustments section of the service manual or owner's manual for the monitor. Adjust monitor as necessary. 3. Third-party monitors: Try a known-good monitor. 4. Reseat the video cable. 5. Reseat the video card. 6. Check the video adapter, if present. 7. Replace the video card.
Screen jitters
1. Verify there are no environmental factors causing jitter. Note: The jitter may be caused by interference from a nearby power line, a fluorescent light, or an external device--for example, a radio, microwave oven, or another computer. Try relocating nearby electrical devices or moving the computer and display. 2. Check all cable connections. 3. Make sure that the video card driver and firmware are updated to the most recent versions. 4. Test with a known-good monitor. Refer to the appropriate monitor manual to troubleshoot a defective monitor. Replace the monitor, if necessary. 5. Reseat the video card. 6. Replace the video card. 7. Replace the logic board.
14 - Power Mac G4 (Mirrored) Troubleshooting
Video Symptom Charts
Sound
No sound from computer's internal speaker
1. Disconnect any microphones or external speakers. 2. Verify the volume is set appropriately in the Sound system preference or Sound control panel and mute is not checked. 3. Clear parameter RAM. Hold down Command-Option-P-R during startup until you hear a second startup chime. 4. Verify the speaker cable is plugged into the logic board. 5. Plug headphones or external speakers into the external jack. If the external jack works, replace the internal speaker. If the external jack doesn't work, replace the logic board.
No sound from Apple Pro Speakers
1. Push on the Apple Pro Speaker jack to make sure it is firmly inserted into the Apple Speaker sound output port. (The Apple Pro Speaker jack has two detents. You should feel them as you push the jack into the sound output port. Giving the jack a slight twist while inserting it into the port may make a better connection.) 2. Verify the speaker volume and balance are set appropriately in the Sound system preference or Sound control panel and mute is not checked. 3. Clear parameter RAM. Hold down Command-Option-P-R during startup until you hear a second startup chime. 4. Reinstall system software. 5. Replace the Apple Pro Speakers. 6. Replace logic board.
Video Symptom Charts
Power Mac G4 (Mirrored) Troubleshooting - 15
Hard Drive
Single internal ATA drive does not spin; flashing question mark on screen
1. Check all cable connections to the hard drive. 2. Try another power connector on the power cable harness. If the power cable is defective, replace the power supply. 3. Replace the hard drive. If the problem is resolved, make sure the driver and system software are updated to the most recent versions.
No internal SCSI drive icon appears on the desktop
1. Check that the drive is listed in Apple System Profiler. If it is, go to step 2. If it is not, go to step 5. 2. Update the drivers. 3. Verify there are no duplicate SCSI device addresses on a single SCSI bus. 4. Disconnect external SCSI devices and check for proper termination. 5. Reseat the SCSI PCI card and verify the cable is seated firmly in the card and drives. 6. Check internal SCSI termination. Internal drives should not be terminated; the SCSI cable should have termination at the end. 7. If more than one SCSI device is on the SCSI chain, remove one device at a time and retest. Replace the bad drive. 8. Replace the internal SCSI data cable. 9. Replace the SCSI PCI card. 10. Verify SCSI drive power by testing different power connector or using a volt meter to check for 12 V/5 V.
No external SCSI drive icon appears on the desktop
1. Verify there are no duplicate SCSI device addresses. 2. Verify the total cable length does not exceed the maximum total cable length for the SCSI card. See Knowledge Base article 58204. 3. Reseat the SCSI cable going to the SCSI card. 4. Replace the terminator on the external SCSI device. 5. Reseat the SCSI card. 6. Replace the SCSI card. 7. Replace the SCSI drive cables one at a time. 8. Disconnect the external SCSI chain. Using known-good cables, reattach devices one at a time.
16 - Power Mac G4 (Mirrored) Troubleshooting
Hard Drive Symptom Charts
Optical Drive
Optical drive tray won't open
1. Reseat the drive data and power cables on the back of the optical drive. 2. Verify the optical drive bezel is properly seated. 3. Reseat the drive data cable on the logic board. 4. Try using a known-good disc. 5. Replace the optical drive.
Unable to eject disc
1. Quit open applications and try to eject disc again. 2. In Mac OS X, choose Restart from the Apple menu and hold down either the mouse button or the Media Eject key on your Apple Pro Keyboard. In Mac OS 9, choose Restart from the Special menu and hold down either the mouse button or the Media Eject key on your Apple Pro Keyboard. 3. Manually eject the disc, as follows: · Shut down the computer. · Open the front panel covering the front of the drive tray and locate a small hole below the drive tray. · Carefully insert the end of a large straightened paper clip into the hole. · Push firmly until the tray opens. · Pull out the tray, remove the disc, and push the tray to close it. 4. If using a third-party keyboard, hold down F12 key.
Optical drive icon does not appear on the desktop
1. Check to see if the optical drive is listed in Apple System Profiler. If it is, go to step 2. If it is not, go to step 7. 2. Try using a known-good disc. 3. If there is a disc stuck in the tray, refer to the symptom "Unable to eject disc". 4. Turn off all third-party extensions. 5. Verify the firmware is the most recent version for that drive. Check Software Downloads for any current update. 6. Reinstall system software. 7. Reseat the drive data and power cables on the back of the optical drive. 8. Try another connector on the power cable harness. If there is a bad connector on the harness, replace the power supply. 9. Replace the optical drive.
Hard Drive Symptom Charts
Power Mac G4 (Mirrored) Troubleshooting - 17
10. Replace the logic board only if other devices on the bus do not work.
USB Devices
At startup, cursor does not move with the Apple mouse
1. Verify that mouse and keyboard connections are secure. 2. If the mouse is connected to the keyboard, connect the mouse to one of the USB ports on the I/O panel instead. If the mouse works, replace the keyboard. 3. Start up from the system installation CD or system restore CD that came with the computer. If the mouse operates, troubleshoot software; refer to the symptom "System quits or stops responding intermittently". 4. If the mouse is connected to one of the USB ports on the I/O panel, switch to the other USB port. If the mouse operates correctly, the first port was bad. Replace the logic board. Note: You can also use Apple System Profiler to verify USB ports. 5. Replace the mouse.
No response to any key on keyboard
1. Verify that keyboard and mouse connections are secure. 2. Remove all USB devices, except the keyboard and mouse. If the keyboard operates correctly, troubleshoot the other USB devices. 3. Switch the keyboard to a different USB port. If the keyboard operates correctly, the first port was bad. Replace the logic board. Note: You can also use Apple System Profiler to verify USB ports. 4. Relaunch Finder. 5. Start up from the system installation CD or system restore CD that came with the computer. If the keyboard operates, reinstall system software. 6. Replace the keyboard. 7. Replace the logic board.
USB printer does not operate
1. Verify that connections to the printer and computer are secure. 2. Switch the printer to a different USB port. If the printer operates correctly, the first port was bad. Replace the logic board. Note: You can also use Apple System Profiler to verify USB ports. 3. Verify the correct versions of the system software and printer driver are installed. 4. Use Print Center to verify that you have the correct printer selected.
18 - Power Mac G4 (Mirrored) Troubleshooting
USB Devices Symptom Charts
5. If the printer is connected to a third-party USB hub, switch it to one of the USB ports on the I/O panel. If the printer operates, the hub is bad. 6. De-install and then re-install the print driver. 7. Replace the printer interface cable. 8. Replace the printer. 9. Replace the logic board.
FireWire Devices
No external FireWire device icon appears on the desktop
1. Verify that the FireWire device is turned on and the FireWire cable is securely connected to the device and the computer. 2. If the device requires external power, make sure it is plugged in. 3. Check that the FireWire device is listed in Apple System Profiler. If it is, go to step 4. If it is not, go to step 5. 4. Check the FireWire device documentation to see if additional drivers are required. If so, make sure the drivers are installed. 5. Check for broken pins, dust, dirt, or wear on both FireWire cable connectors, the device FireWire port, and the computer FireWire port. 6. Re