Power Macintosh 9500 General Maintenance

Power Macintosh 9500/132. Photo: Thomas Kaiser, Wikimedia Commons, CC BY-SA 3.0

These procedures for the Power Macintosh 9500 come from Apple's Power Macintosh 9500 Series Service Source. The 9500 uses a taller version of the Power Macintosh 8100 and 8500 case, and its power supply and many procedures match the 8500's (Power Macintosh 8500 General Maintenance). The logic board stands upright on the left as seen from the rear. Seen from the front, the processor card plugs into it on the left beneath the power supply, and the PCI cards and the fan are on the same side (SS pp. 90, 92, 96, 104).

Apple warns never to run the computer with the top housing removed, or internal components can be damaged beyond repair (SS p. 65). The supply carries mains voltage whenever the computer is plugged in; unplug it before opening the case.

Opening the case

Loosen the six captive screws on the rear panel, slide the top housing forward and lift it straight up (SS pp. 66–67). For the fan, the processor card and the PCI cards, lay the computer on its side with the power supply facing up (pp. 90, 92).

Fan

The fan clips to the bottom chassis on the left side and plugs into the logic board. Unplug its cable from the board, squeeze the two plastic latches at the top of its bracket, pull the fan down and push it to the right off the plastic stays. To refit it, hold it at 90 degrees to the chassis, fit its bottom pins into the stays and swing it upright; plug it back into the logic board (SS pp. 104–107). Apple's chart for intermittent shutdowns includes checking that the fan is plugged in and turning (p. 46).

Processor card and PCI cards

Remove the fan first. Grip the processor card by its corners (and the top of the heat sink if it is cool) and pull it straight up; the heat sink may be hot. To refit it, position the bottom edges in the plastic guides and press down evenly without forcing it (SS pp. 90–91). PCI cards, including the Apple Accelerated Graphics card, are held by plastic latches; push the latches apart and lift the card. Before sending a graphics card away, take off any third-party VRAM module; when refitting the module, line up the arrows on the two cards and press gently (pp. 92–95). Residue on a card's edge connector can cause faults; inspect it with a magnifier and clean it with a pencil eraser (p. 40).

Memory

The twelve DIMM slots take 5 V, 168-pin, 64-bit, 70 ns fast-page DIMMs. Fill slot A6 first, then B6, then A5 and B5, and so on, leaving A1 and B1 until all the others are full. DIMMs work singly, but interleaving needs matching pairs in paired slots (SS pp. 12–14, 43). Each DIMM seats with a double click; push it fully home (pp. 11, 103). The logic board has to come out to reach the slots.

Logic board

Remove the top housing, fan, processor card and PCI cards first (SS p. 96).

1. Disconnect all the cables from the top of the board: the two power supply cables and the floppy, CD-ROM audio, speaker and SCSI cables.
2. Press in the two plastic tabs on the power actuator at the bottom of the board and remove it.
3. Remove the screw that secures the board to the chassis.
4. Slide the board forward until its slot lines up with the latch on the chassis, lift the latch at the top and pivot the front of the board out.
5. Disconnect the LED cable, which runs to the power actuator.

Remove the DIMMs before sending a board away, but leave the ROM SIMM (pp. 97–103). When fitting a board, make sure the LED cable does not obstruct the power actuator (pp. 41–60).

Clock battery and resets

The battery sits in a holder on the logic board, so the board must come out to reach it; prise open the latch at the end of the holder and lift off the cover (SS p. 19). The service parts are battery 922-1262 and cover 520-0344 (p. 111), and Apple's specification pages give the battery as 3.6 V lithium. This Service Source gives no voltage below which to replace it. Neutralise residue from a leaking lithium cell with bicarbonate of soda solution and rinse with isopropyl alcohol; see Battery Explosion, Capacitor or Corrosion Damage and Battery Refurbishment.

Press the red Cuda reset button on the logic board to reset the chip that controls power, resets, PRAM, ADB and the clock (SS p. 18). Apple's logic board reset (pp. 19–20):

1. Unplug the computer and remove the logic board.
2. Open the battery holder and take out the battery.
3. Check that the power supply cable is disconnected from the board and press the Power On button.
4. Wait at least 10 minutes, refit the battery the right way round, reassemble and test. Set the date and time again afterwards.

Power supply

The supply sits at the back of the chassis beneath the speaker. Disconnect its two cables from the logic board: the 10-pin cable carries 3.3 V for the processor card and the 22-pin cable 5 V and ±12 V. Turn the computer so the supply is on your left, push in the latch on the right of the chassis support brace and pull the brace out, then push in the plastic latch beside the supply and slide the supply forward and out. When refitting, feed the two metal tabs at the back of its bottom edge through the openings in the chassis first (SS pp. 77–82). The supply is automatically configured for 100–240 V (p. 35); the service part is 661-0923 (p. 111).

Drives

The CD-ROM drive is in the top bay, the floppy drive in the second and the hard drive in the bottom bay; each slides forward once its retaining clip at the back is released (SS pp. 68–76). Only the last device on each SCSI chain is terminated (p. 55). See Hard Drive Maintenance and Repair and Floppy Drive Repair.

Related pages

• Power Macintosh 9500
• Power Macintosh 9500 Troubleshooting
• Power Macintosh 8500 General Maintenance
• Power Macintosh 9600 General Maintenance
• Recommended Tools