Apple Network Server 500 and 700 General Maintenance

Network Server main logic board (photo: Cameron Kaiser, Old Vintage Computing Research)

Maintenance for the Apple Network Server 500 and 700 (Apple Network Server 500 and Apple Network Server 700), which share one case, logic board and service manual. The procedures follow Apple's Service Source for the Network Server 500 and 700 Series and chapter 11 of Apple's Service Guide volume V, with notes from Cameron Kaiser's work on his own 500 and 700.

Before you start

• The server weighs 84 to 92 lb (38 to 41 kg) depending on the drives fitted, and stands on locking wheels.
• Disconnect the power cord before every procedure except swapping a fan or, on a 700 with two supplies, a power supply.
• Turning the rear key to unlock the drawer powers the system down; Apple's procedures still begin by disconnecting the power cord.
• Put the drawer on an antistatic mat. Kaiser notes that the board is ungrounded once the drawer is out.
• Do not run the server with the top cover or either side panel off. Apple warns that it may cause irreparable damage to internal components.

Keys and access

Apple's front view locator (Service Guide volume V, p. 220)

The front key has three positions. Apple's keylock matrix gives what each one opens:

Front keylock positions (Service Source, p. 68)

Position	Parts that can be reached
Left (service)	Front door, base door, power supply, top shelf, bottom shelf
Upright (unlocked)	Front door, base door, rear drawer, power supply, front bezel assembly, top shelf, bottom shelf
Right (locked)	Drive trays, if the front door is positioned properly

Turn the front key to upright or left before taking off the base door, or the lock shaft may be damaged. The base door comes off by pressing the two buttons on its left and right inside edges and pulling it out.

The rear key works the drawer. In the horizontal (locked) position the board is connected and a metal tab holds the drawer in; in the vertical position the board is disconnected and the drawer can be pulled. Kaiser notes that the key will not turn to locked unless the board is fully engaged with the mezzanine and power connectors. The original keys are wafer-lock keys with a three-digit code engraved on them, of the type used on the Macintosh Quadra 950, and all three keys supplied with a server are interchangeable.

Rear drawer

The drawer carries the fan assembly, rear I/O panel, rear keyswitch cable, logic board with its cards, logic board carrier and processor card guides. Support it whenever it is out, or it can fall off the slides.

1. Disconnect the power cord.
2. With the back of the server facing you, turn the rear key to the upright (unlocked) position.
3. Loosen the four thumbscrews and slide the drawer out a few inches.
4. Holding the top handle with the right hand, release the bottom black latch with the left and move the bottom drawer slide 1 inch to the left. Repeat for the top latch and slide.
5. Lift the drawer off the slides and put it on an antistatic mat.

To refit it, hold the top handle and align the bottom slide between the drawer's mounting rail and the plastic guide, so that the hook at the far left of the slide engages the notch in the rail; then move the slide fully to the right until the black latch clicks. Press the carrier against the slides and do the same with the top slide. Kaiser adds that on each slide one hook engages: the bottom hook on the top slide and the top hook on the bottom slide.

For battery, memory, cache and card work the drawer only needs to slide out; it does not have to come off.

Kaiser found the drawer would not open far enough because of broken plastic pieces in the slides and the original lubricant, which had dried to a sticky copper-coloured residue. He cleaned the rails, worked white lithium grease into the bearings and wiped off the excess. The slides are Apple part 922-2133.

Fans and airflow

Two fans in the rear panels cool the machine; both are hot-swappable and can be changed without tools while the server runs. Temperature sensors on the logic board shut the server down if a fan fails and the cabinet overheats. The LCD names the failed fan: "Drive Fan Failed!" for the fan on the right when facing the rear, "Processor Fan Failed" for the fan on the left when facing the unit.

To change a fan, put your fingers in the notch on the fan assembly from the back, press it down and away from the unit. Fit the new one at a right angle to the unit, insert its tab first, push it up into the enclosure and check that its bottom contacts are seated. The LCD shows when it is safe to replace the assembly. The fan is Apple part 922-2142.

Keep the vents clear and every drive tray, including the blank trays in empty bays, fully inserted. Apple's chart for intermittent shutdowns starts with the fans, fully inserted drive trays ("improper installation may disrupt air flow") and clear vents, and notes that the thermal protection circuit should let the server run again after 30 to 40 minutes.

When refitting the rear panel, reconnect the fan-to-SCSI-backplane cable to the correct connector. Apple warns that the rear drives' power connector is similar, and that with the fan cable on it the server will not power on.

Cleaning

• Blow dust out of the fan grilles, the power supply bays and the drawer with compressed air, with the cord out.
• Apple notes that a small number of cards for the Network Server have residue on their gold edge connectors that causes intermittent faults. Inspect the pins with a magnifier and clean any residue gently with a pencil eraser.
• Clean DIMM, cache and ROM sockets with a contact cleaner such as DeoxIT D5 and let them dry before power-up.
• Most of the case is painted metal; Kaiser's 700 had yellowed where it had been in the sun. For the plastic parts see Retrobrite.

Clock battery

Apple's logic board figure, showing the battery holder and Cuda reset button at the bottom edge (Service Guide volume V, p. 217)

The PRAM and clock run from a 3.6 V lithium cell, Apple part 922-1262 (without leads), in a holder on the logic board next to the red Cuda reset button. The holder cover is 520-0344. Apple's general power-fault chart for the volume says the battery must read 3.2 V or more.

1. Disconnect the power cord.
2. Turn the rear key upright, loosen the four thumbscrews and slide the drawer out. Leave it on its slides.
3. Lift off the battery cover with a small screwdriver and take out the cell.
4. Fit the new cell the right way round and refit the cover.

Taking the battery out also resets PRAM, so check the date and time afterwards. A leaking cell destroyed the logic board of Kaiser's prototype while it was stored with the battery fitted, and he keeps the batteries out of his machines in storage. For cleaning up after a leak see Battery Explosion, Capacitor or Corrosion Damage.

The optional PCI RAID card has its own backup battery for its cache, Apple part 661-1183. When replacing a RAID card, move the card's DRAM SIMM (661-1184) to the new card.

Memory, cache and processor card

• DIMMs: 168-pin, 72-bit fast-page-mode parity DIMMs of 60 ns or faster, which must support byte writes, in matched pairs (one in 1A, one in 1B, and so on) for interleaving. Non-parity 70 ns DIMMs work, but any one of them turns off parity checking for all memory. SIMMs and some DIMMs from Macintosh computers do not fit or do not work. The limit is 512 MB. To remove one, push the ejector tab next to the socket out and down; some boards have a tab at each end. Fit the new DIMM with the tab down and do not force it.
• Apple's own DIMMs are 8 MB (661-1128), 16 MB (661-1129) and 32 MB (661-1130), 60 ns parity. Kaiser notes that Apple's memory kits were made by IBM.
• Cache: 512 KB (661-0927) on the 500, 1 MB (661-1127) on the 700, 160-pin. Grasp the cache DIMM by its edges to pull it. Kaiser's 500 kernel-panicked with a Sonnet cache upgrade and ran with a 1 MB cache from a 700.
• Processor card: hold it by its edges, never by the heat sink, and support the drawer while pulling it, which takes some force. To fit one, set its lower edges in the card guides, slide it in until it meets the connector and press it fully home without forcing it; Apple warns that the server will not start with the card partly seated.

Apple's logic board return note says to leave the ROM SIMM on the board and remove the processor card, card guides, DIMMs, cache and PCI cards.

Power supplies

Network Server power supplies (Apple)

Model	Supply	Apple part	Assembly number	Connection
500	One 325 W	661-1145	614-0038	Two cables to the logic board: 22-pin (+5 V, ±12 V) and 10-pin (3.3 V for the processor card)
700	One or two 425 W, hot-swappable	661-1131	614-0051	No cables; plugs into the power backplane

Rated output current (Service Source, Specifications p. 12)

Output	500	700
+3.3 V	25.0 A	50.0 A
+5 V	28.0 A	44.0 A
+12 V (normal)	11.0 A	13.0 A
+12 V (start-up)	18.0 A for 12 seconds maximum
−12 V	100 mA	100 mA
+3.3 V and +5 V together	180 W	260 W

The PCI allowance is 10 A at +3.3 V, 10 A at +5 V and 2 A at +12 V, 50 W in total, on the 500, and 18 A, 18 A and 2 A, 90 W in total, on the 700; no single card should exceed the 25 W of the PCI 2.1 specification. Each drive bay averages 1.1 A at +5 V and 1.3 A at +12 V, and Apple recommends setting drives to spin up on command.

On the 700, pull a supply from the front after setting the front key upright or left and removing the base door. With two supplies fitted it can be done with the server running; the LCD shows when it is safe. Push a replacement all the way into the bay until it snaps in. The 500's supply is reached only after removing the base door, rear drawer, rear panel, top cover, both side panels, the left duct and the AC interlock ground cable; it then comes out after its power backplane cable, ground cables and logic board cable are disconnected and its screw is removed.

Warning: the supplies contain mains voltage and charged capacitors. Apple's documents give no schematic or component list for them.

Drives

Every drive in a front bay sits in a carrier with a drive interconnect board, and a SCSI ID cable from the carrier sets the drive's ID for that bay. The cable type depends on the drive:

SCSI ID cables (Service Guide volume V, parts list)

Cable	Apple part	Used with
Type 1	922-2102	2, 4 and 9 GB hard drives (661-0956, 661-0958, 661-1178, 661-1179, 661-1246, 661-1247) and the 8 mm tape drive
Type 2	922-2103	DDS-2 DAT drive 661-0039
Type 3	922-2104	CD-ROM drives 661-1167 and 661-1240
Type 4	922-2099	1.2 GB hard drive 661-1142

The Type 1 cable has a six-pin and a four-pin connector, and IBM and Seagate drives take it in different orientations (Figure 89 in the Service Guide). For a Quantum drive, or any drive with an active-high LED signal, move the wire from pin 3 of the drive tray connector to pin 1 before connecting it. Third-party drives fit in an Apple carrier with the 50-pin or 68-pin cable, SCSI ID cable, power cable and LED cable; Apple sold a SCSI drive adapter kit (M4028Z/A) and a front bezel kit for tape and CD-ROM drives (M4029Z/A).

The internal SCSI cable is terminated, so disable termination on every drive fitted in a front bay. Hot-swapping drives is safe only with the PCI RAID card installed. In the 700's rear bracket, the bottom drive is terminated through its SCSI ID cable and the last connector on the ribbon cable; a lone drive goes on the last connector.

The 8 mm tape drive reads but cannot write standard metal-particle tapes, and its heads must be cleaned after reading one before an AME tape is used. On the DDS-2 DAT drive, a failed self-test with the right light flashing amber calls for a head clean, and an amber flash when a tape is loaded means the tape is worn out.

Capacitors

Apple publishes no component list for the logic board, processor card or power supplies. Kaiser reports a 200 MHz processor card that stayed dead after a recap and fresh heat-sink compound. For the general signs of failing electrolytics see Capacitor Failure Symptoms.

Related pages

• Apple Network Server 500
• Apple Network Server 700
• Apple Network Server 500 and 700 Troubleshooting
• Apple Network Server 500 and 700 Documentation
• Recommended Tools
• Hard Drive Maintenance and Repair