Apple Macintosh Powermac Performa WS8550 Service Manual

K

Service Source

Power Macintosh 8200 and

8500 Series/WS 8550

Power Macintosh 8200 Series (Europe Only), 8500

Series, and WS 8550 Series

K

Service Source

Basics

Power Macintosh 8200 and 8500

Series/WS 8550 Series

Basics Overview - 1

Overview

This manual covers the Power Macintosh 8200 Series
(available only in Europe), the Power Macintosh 8500
Series, and the WorkGroup Server 8550 Series computers.
These computers all share the same form factor as the
earlier Power Macintosh 8100.

Power Macintosh 8200 Series

The Power Macintosh 8200 Series computers are available
only in Europe. There are two versions of the Power
Macintosh 8200, the Power Macintosh 8200/100 and the
8200/120. Features of the Power Macintosh 8200 Series
include

• A 100 or 120 MHz PowerPC™ 601 microprocessor on
the logic board with built-in FPU and 32K on-chip cache

Basics Overview - 2

• 256K level 2 cache

• 16 MB of DRAM, expandable to 256 MB

• Three PCI expansion slots

• SCSI DMA bus that supports up to four external and
three internal SCSI devices

• Built-in AAUI and 10BASE-T Ethernet support

• Support for AppleTalk and TCP/IP networking protocols

• Two GeoPort serial ports

• AppleCD™ 600i 4x CD-ROM drive

• 16-bit stereo sound input/output

• 1 MB of soldered VRAM

• Mac™ OS system software 7.5.3

Basics Overview - 3

Power Macintosh 8500/WS 8550

The Power Macintosh 8500 and Workgroup Server 8550
feature three PCI expansion slots, a removable 604
microprocessor card, and, in addition, the Power Macintosh
8500 features video in and out functionality standard.

The list of features for the Power Macintosh 8500 includes

• A 120, 132, 150, or 180 MHz PowerPC™ 604
microprocessor card with built-in FPU and 32K on­chip cache

• Three PCI expansion slots

• One Digital Audio Video (DAV) slot

• 10 MB per second internal SCSI channel, 5 MB per
second external SCSI channel

• 256 K Level 2 cache

• DRAM expansion up to 512 MB using 168-pin, 70 ns,
64-bit DIMMs

Basics Overview - 4

• 2 MB of VRAM, expandable to 4 MB

• 24-bit composite and S-video input and output

• Built-in AAUI and 10BASE-T Ethernet

• Two GeoPort serial ports

• AppleCD™ 600i 4x CD-ROM drive or 1200i 8x CD-ROM
drive (8500/150 8x CD and 8500/180)

• 1.4 MB floppy drive

• CD-quality stereo sound in/out

• Mac™ OS system software 7.5.2 (8500/120) or 7.5.3
(8500/132 and 8500/150) or 7.5.3 Revision 2
(8500/150 8x-CD and 8500/180)

The list of features for the Workgroup Server 8550 Series
computers includes

• A 132 MHz or 200 MHz PowerPC™ 604 microprocessor
card with built-in FPU and 32K on-chip cache

• 512K Level 2 cache

Basics Overview - 5

• 24 MB of DRAM, expandable to 512 MB using 168-pin,
70 ns, 64-bit DIMMs

• Two SCSI DMA buses supporting up to eight SCSI devices
and transfers up to 10 MB/s (internal bus only)

• Three PCI expansion slots

• Built-in AAUI and 10BASE-T Ethernet

• Two GeoPort serial ports

• AppleCD™ 600i or 1200i CD-ROM drive

• 2 GB hard drive, with bracket and cable for a second
drive (support for array drives)

• DDS-2 DAT drive (optional)

• 1.4 MB floppy drive

• CD-quality stereo sound in/out

• Built-in 2 MB VRAM display support

• Support for TCP/IP networking software with Apple
Open Transport

• Mac™ OS system software 7.5.3 (8550/132) or 7.5.3
Revision 2 (8550/200)

Basics Configurations - 6

Configurations

The Power Macintosh 8500/120 comes standard with

• 120 MHz PowerPC 604 microprocessor card

• 16 MB of DRAM

• 256K Level 2 cache DIMM

• 1 GB or 2 GB hard drive

• AppleCD 600i CD-ROM drive

• 2 MB of VRAM

The Power Macintosh 8500/132, 8500/150, and
8500/180 come standard with

• 132, 150, or 180 MHz PowerPC 604 microprocessor
card

• 16 MB of DRAM (8500/132) and 16 or 32 MB of DRAM
(8500/150 and 8500/180)

• 256K Level 2 cache DIMM

Basics Configurations - 7

• 1.2 GB or 2 GB hard drive

• AppleCD 600i 4x CD-ROM drive (8500/120, 8500/
132, and 8500/150) or 1200i 8x CD-ROM drive
(8500/150 8x-CD and 8500/180)

• 2 MB of VRAM

The WS 8550/132 and 8550/200 come standard with

• 132 MHz (8550/132) or 200 MHz (8550/200)
PowerPC 604 microprocessor card

• 24 MB of DRAM

• 512K Level 2 cache DIMM

• 2 GB hard drive

• AppleCD 600i (8550/132) or 1200i (8550/200)
CD-ROM drive

• 2 MB of VRAM

Basics PowerPC 601 Microprocessor - 8

PowerPC 601 Microprocessor

The Power Macintosh 8200 Series computers feature the
PowerPC 601 RISC microprocessor built onto the logic
board. Features of this microprocessor include

• Full RISC processor architecture

• 32-bit addressing

• 64-bit data bus

• Built-in FPU

• 32K cache for data and instructions

• Internal Memory Management Unit (MMU)

• Advanced branching techniques for improved throughput

Basics PowerPC 604 Microprocessor - 9

PowerPC 604 Microprocessor

The Power Macintosh 8500 and WS 8550 computers feature
the PowerPC 604 RISC microprocessor. The PowerPC 604
microprocessor is installed via a card that plugs into the
logic board, allowing for maximum flexibility with future
upgrades.

Features of this microprocessor include

• Full RISC processing architecture

• Parallel processing units: one load-store unit, two
integer units, one complex integer unit, and one floating
point unit

• Separate built-in caches for data and instructions, 16
KB each, four-way set associative

• Advanced branching techniques for improved throughput

Basics Peripheral Component Interconnect (PCI) - 10

Peripheral Component Interconnect (PCI)

The Power Macintosh 8200 Series, Power Macintosh 8500
Series, and WS 8550 computers offer a Peripheral
Component Interconnect (PCI) expansion bus. Because the
PCI bus is an industry standard, most existing PCI 2.0­compliant cards (with the addition of a Mac OS-specific
software driver) will work in these computers.

PCI offers significantly higher performance than the NuBus
architecture used in previous Macintosh models. Running at
33 MHz, the PCI bus is up to three times faster than NuBus,
offering overall enhanced system performance, particularly
in the areas of video and networking.

Basics Dual In-Line Memory Modules (DIMMs) - 11

Dual In-Line Memory Modules (DIMMs)

The Power Macintosh 8200 Series, Power Macintosh 8500
Series, and WS 8550 computers use DRAM Dual In-Line
Memory Modules (DIMMs) instead of DRAM SIMMs.
Whereas SIMMs have 72 pins, DIMMs have 168 pins. The
extra pins provide a 64-bit data path, compared to a 32-bit
data path for SIMMs. In addition, DIMMs do not have to be
installed in pairs like the SIMMs on earlier Macintosh
models. (However, to take advantage of memory
interleaving, the DIMMs should be installed in paired slots.
See "Memory Configurations" in Basics for more
information.)

Important:

used in previous Macintosh models are
these computers.

The Single In-Line Memory Modules (SIMMs)

not

compatible with

Basics Memory Configurations - 12

Important

pin 70 ns or faster) instead of VRAM SIMMs. The VRAM
SIMMs used in earlier Power Macintosh models are
compatible.

: These computers also use VRAM DIMMs (112-

not

Memory Configurations

Following is the memory configuration information for the
computers covered in this manual.

Power Macintosh 8200 Series

The Power Macintosh 8200 Series logic boards have four
DRAM DIMM slots, each with a 64-bit data bus. You can
increase the computer’s DRAM to a total of 256 MB using 5­volt, 64-bit-wide, 168-pin fast-paged mode, 70 ns
DIMMs.

Basics Memory Configurations - 13

Note:

These computers do not have any main memory
soldered to the logic board. At least one DRAM DIMM must be
present for the computer to operate.

DRAM DIMMs can be installed individually or in pairs. These
computers support linear memory only; therefore, no
memory gains are seen when two DIMMs of the same size are
installed (that is, memory interleaving is not supported on
the Power Macintosh 8200 Series computers).

Note: DIMMs purchased from different manufacturers can

be paired; However, Apple recommends that you use DIMMs
of the same size and speed.

The drawing on the next page illustrates where the DRAM
slots are located on the Power Macintosh 8200 Series logic
boards and how they are numbered. DRAM can be installed in
any order.

Basics Memory Configurations - 14

4
3
2
1

Figure: PM 8200 Series DRAM DIMM Slots

Basics Memory Configurations - 15

Power Macintosh 8500 Series/WS 8550

The Power Macintosh 8500 and WS 8550 logic boards have
eight DRAM DIMM slots, each with a 64-bit data bus. You
can increase the DRAM to a total of 512 MB using 5-volt,
64-bit-wide, 168-pin fast-paged mode, 70 ns DIMMs.

Note:

These computers do not have any main memory
soldered to the logic board. At least one RAM DIMM must be
present for the computers to operate. DRAM DIMMs can be
installed individually; however, if you wish to take
advantage of the computer’s interleaving* capability, which
provides maximum performance, you must install the
DIMMs in matching pairs and in paired slots (A4 and B4, A3
and B3, and so on).

* Memory interleaving allows the computer to read or write
to its memory while other memory reads or writes are
occurring, thus providing for faster performance.

Basics Memory Configurations - 16

For a pair of DIMMs to function as a single 128-bit wide
pair, they must be the same type and size.

Note:

DIMMs purchased from different manufacturers can

be paired as long as they are the same size and speed.

The drawing on the next page illustrates where the DRAM
slots are located on the Power Macintosh 8500 and WS
8500 logic boards and how they are numbered.

Basics Memory Configurations - 17

B4 slot
B3 slot
B2 slot
B1 slot
A4 slot

A3 slot
A2 slot

A1 slot

(front of computer)

Figure: PM 8500 and WS 8550 DRAM DIMM Slots

Basics Ethernet Support - 18

Ethernet Support

There are two Ethernet ports on the Power Macintosh 8200,
Power Macintosh 8500, and WS 8550 logic boards: an AAUI
port and a 10BASE-T port. You can use only one Ethernet
port at one time, however. If you have cables plugged into
both Ethernet ports, the computer uses the 10BASE-T port
by default.

AV Support

The Power Macintosh 8500 comes standard with an AV
module that provides support for: composite video input and
output, S-video input and output, audio input (left and
right), and audio output (left and right).

Basics GeoPort - 19

GeoPort

Geoport is a hardware and software communications
architecture that has been optimized for computer­telephony integration. It has three main attributes:

• It lets any computer connect to any telephone (analog or

digital, public or private) anywhere in the world.

• Once connected, it supports an arbitrary number of

independent data streams up to a total bandwidth of
2 MB/second.

• Unlike traditional asynchronous data communications

(such as AppleTalk), GeoPort also supports isochronous
data streams (such as real-time voice and video) and
provides the real-time Application Program Interfaces
(APIs) necessary to hide the implementation details
from both the recipient and the sender.

Basics PC Compatibility Cards - 20

By attaching an Apple GeoPort Telecom Adapter to these
computers, you can enjoy all the features of a 14.4 modem,
including data, fax, send and receive, and voice capabilities.
The GeoPort Telecom Adapter serves as a line interface to
standard (analog) telephone lines. The adapter is capable of
sending or receiving data at up to 14.4 kbps and faxes at up
to 9600 bps using the GeoPort Telecom Adapter software.

PC Compatibility Cards

Apple computer offers two PC Compatibility Card upgrade
kits that bring full DOS functionality to the Macintosh
computer. Two versions of the PC Compatibility card are
available: a 7" card and a 12" card. The cards plug into any
available PCI slot on the logic board. Refer to the Upgrades
chapter in this manual for installation instructions.

Basics The Cuda Chip - 21

The Cuda Chip

The Cuda is a microcontroller chip. Its function is to

• Turn system power on and off

• Manage system resets from various commands

• Maintain parameter RAM (PRAM)

• Manage the Apple Desktop Bus (ADB)

• Manage the real-time clock

Many system problems can be resolved by resetting the Cuda
chip (see Symptom Charts for examples). Press the Cuda
reset button on the logic board to reset the Cuda chip. (See
"Logic Board Diagram" later in this chapter to locate the
Cuda reset button.) If you continue to experience system
problems, refer to "Resetting the Logic Board" later in this
Basics chapter.

Basics Resetting the Logic Board - 22

Resetting the Logic Board

Resetting the logic board can resolve many system problems
(refer to "Symptom Charts" for examples). Whenever you
have a unit that fails to power up, you should follow this
procedure before replacing any modules.

1 Unplug the computer.

2 Remove the logic board. (Refer to the Take Apart chapter

for instructions on how to remove the logic board.)

3 Using a small flat-blade screwdriver, pry open the latch

at the end of the battery holder and lift off the battery
holder cover.

4 Remove the battery from its holder.

Basics Resetting the Logic Board - 23

5 Verify the power supply cable is disconnected from the

logic board and then press the Power On button. (See
"Logic Board Diagram" later in this chapter to locate the
Power On button.)

6 Wait at least 10 minutes before replacing the battery.

Make sure the battery is installed in the correct +/­direction.

7 Reassemble the computer and test the unit.

Note:

This procedure resets the computer’s PRAM. Be sure
to check the computer’s time/date and other system
parameter settings afterwards.

Note:

If this procedure resolves the problem, claim an
adjustment on an SRO. If not, replace the defective
component and DO NOT claim the adjustment procedure.

Basics Fast SCSI - 24

Fast SCSI

The Power Macintosh 8500 and WS 8550 computers offer
Fast SCSI support on the internal SCSI connector, which
provides for significantly enhanced data throughput. The
internal SCSI bus on these computers supports transfer
rates up to 10 MB/sec.

Basics Rear View Diagram - 25

Rear View Diagram

The Power Macintosh 8200 and WS 8550 computers offer
the following external ports: SCSI, AAUI and 10BASE-T
Ethernet, serial printer (GeoPort compatible), serial
modem (GeoPort compatible), DB-15 video, ADB, sound
input, and sound output.

The drawing on the following page illustrates the back panel
of the Power Macintosh 8200 and WS 8550 computers.

Basics Rear View Diagram - 26

SCSI

AAUI Ethernet

10 BASE-T Ethernet

Printer
Modem
Monitor

ADB

Sound in

Sound out

Figure: Power Macintosh 8200 and WS 8550 Rear Panel

Basics Rear View Diagram - 27

In addition to the ports shown on the previous page, the
Power Macintosh 8500 offers composite video input and
output, S-video input and output, audio input (left and
right), and audio output (left and right) ports.

The drawing on the following page illustrates the back panel
of the Power Macintosh 8500 computer.

Basics Rear View Diagram - 28

SCSI

AAUI Ethernet

10 BASE-T Ethernet

Printer
Modem
Monitor

ADB

Sound in

Sound out

S-video

Composite video

Audio output 
(left &right)

Audio input 
(left & right)

Figure: Power Macintosh 8500 Rear Panel

Basics Logic Board Diagram - 29

Logic Board Diagram

The following graphics illustrate the connectors on the
Power Macintosh 8500, WS 8550, and Power Macintosh
8200 logic boards.

Note:

Some versions of the logic board have a ROM SIMM
while other versions have the ROM soldered on the logic
board.

Basics Logic Board Diagram - 30

External SCSI

VRAM Slots

AAUI Ethernet

10BASE-T

Ethernet

Modem (top)/

Printer (bottom)

Video

ADB

Cuda Reset

Sound Out (top)/

Sound In (bottom)

PCI Slots

Internal

SCSI

Power

Supply

AV Module

Speaker

Processor
Card Slot

CD

Audio

DAV

Floppy

Drive

Figure: Power Macintosh 8500 Logic Board

3.3V Power
Supply

ROM
SIMM

DRAM
Slots

Cache
DIMM 

DRAM
Slots

Battery

Power
LED


Power
On/Off



Basics Logic Board Diagram - 31

External SCSI

VRAM Slots

AAUI Ethernet

10BASE-T

Ethernet

Modem (top)/

Printer (bottom)

Video

ADB

Cuda Reset

Sound Out (top)/

Sound In (bottom)

PCI Slots

Figure: Workgroup Server 8550 Logic Board

Internal

SCSI

Power

Supply

Speaker

Processor
Card Slot

CD

Audio

DAV

Floppy

Drive

3.3V Power
Supply

ROM
SIMM

DRAM
Slots

Cache

DIMM

DRAM
Slots

Battery

Power
LED

Power
On/Off

Basics Logic Board Diagram - 32

External SCSI

AAUI Ethernet

10BASE-T

Ethernet

Modem (bottom)

Printer (top)

Video

ADB

Sound Out (top)

Sound In (bottom)

PCI Slots

Cuda Reset

Figure: Power Macintosh 8200 Logic Board




Internal

SCSI

Power

Supply

CD

Audio

Floppy

Drive

3.3V Power
Supply

4
3
2
1

3
2
1

PowerPC 601 Processor Speaker

Battery

DRAM Slots
VRAM Slots

Cache DIMM 
ROM SIMM

Power LED


Power
On/Off



Basics Repair Strategy - 33

Repair Strategy

Service the Power Macintosh 8500 and WS 8550 computers
through module exchange and parts replacement. Customers
can request on-site service from an Apple Authorized
Service Provider Plus (AASP+) or Apple Assurance. They
can also choose carry-in service from an AASP.

Ordering

Apple Service Providers planning to support the Power
Macintosh 8500 and WS 8550 computers may purchase
Service modules and parts to develop servicing capability.
To order parts, use the AppleOrder system and refer to the
Power Macintosh 8500 or Workgroup Server 8550
"Service Price Pages."

Basics Ordering - 34

Large businesses, universities, and K-12 accounts must
provide a purchase order on all transactions, including
orders placed through the AppleOrder system. Service
providers not enrolled in AppleOrder may fax their orders
to Service Provider Support (512-908-8125) or mail
them to

Apple Computer, Inc.
Service Provider Support
MS 212-SPS
Austin, TX 78714-9125

If you have further questions, please call Service Provider
Support at 800-919-2775 and select option #1.

Basics Warranty and AppleCare - 35

Warranty and AppleCare

The Power Macintosh 8500 and WS 8550 computers are
covered under the Apple One-Year Limited Warranty. The
AppleCare Service Plan is also available for these products.
Service Providers are reimbursed for warranty and
AppleCare repairs made to these computers. For pricing
information, refer to "Service Price Pages."

K

Service Source

Specifications

Power Macintosh 8200 and 8500

Series/WS 8550 Series

Specifications Processor - 1

Processor

CPU

PM 8200

PM 8500

PowerPC 601 RISC microprocessor running at 100 or 120 MHz
Built-in FPU and 32K cache
Requires system software version 7.5.3 or later with appropriate

System Enabler

PowerPC 604 RISC microprocessor running at 120, 132, 150 or

180 MHz
Built-in FPU and 32K cache
Requires system software version 7.5.2 or later (8500/120),

7.5.3 or later (8500/132 and 8500/150) with appropriate

System Enabler, and 7.5.3 Revision 2 (8500/150 8x-CD and

8500/180)

Specifications Processor - 2

WS 8550

PowerPC 604 RISC microprocessor running at 132 or 200 MHz
Built-in FPU and 32K cache
Requires system software version 7.5.3 or later with appropriate

System Enabler (8550/132) or 7.5.3 Revision 2 or later

(8550/200)

Specifications Memory - 3

Memory

DRAM

PM 8200/100 and 8200/120

PM 8500/120 and 8500/132

PM 8500/150 and
8500/180

WS 8550

8 MB or 16 MB standard; expandable to 256 MB
Uses 168-pin, 64-bit, 70 ns or faster DRAM DIMMs

16 MB standard; expandable to 512 MB
Uses 168-pin, 64-bit, 70 ns or faster DRAM DIMMs

16 or 32 MB standard; expandable to 512 MB
Uses 168-pin, 64-bit, 70 ns or faster DRAM DIMMs

24 MB standard; expandable to 512 MB
Uses 168-pin, 64-bit, 70 ns or faster DRAM DIMMs

Specifications Memory - 4

ROM

Cache

PM 8200

PM 8500

WS 8550

Clock/Calendar

4 MB ROM (may be installed in ROM SIMM slot, or soldered on the

logic board)

256K Level 2 cache DIMM

256K Level 2 cache

512K Level 2 cache

CMOS custom circuitry with long-life battery

Specifications I/O Interfaces - 5

I/O Interfaces

SCSI

PM 8500 and
WS 8550

Serial

ADB

Ethernet

Dual-channel asynchronous SCSI interface; external channel

supports up to seven SCSI devices
Internal channel supports a hard disk array

Two RS-232/RS-422 serial ports compatible with LocalTalk and

GeoPort cables; mini DIN-8 connectors

One Apple Desktop Bus port for a keyboard, mouse, etc.

One AAUI and one 10BASE-T Ethernet port (if cables are plugged

into both ports, system defaults to 10BASE-T)

Specifications I/O Interfaces - 6

Expansion

Sound

Video

PM 8500

Three PCI expansion slots, compatible with all PCI 2.0

specification-compliant cards with the addition of Mac OS-

specific software driver (not NuBus compatible)

16-bit stereo sound input and output ports

Built-in DB-15 video connector on logic board
24-bit video input and output connectors on AV module

Specifications I/O Devices - 7

I/O Devices

Keyboard

Mouse

Microphone

Standard, extended, or adjustable keyboard; keyboard draws

25-80 mA, depending on model type

ADB Mouse II; mouse draws up to 10 mA

Apple PlainTalk microphone standard

Specifications Video Support - 8

Video Support

Table 1: PM8500 and WS 8550 Video Support

PIXEL DEPTHS

MONITOR DISPLAY SIZE 2 MB VRAM 4 MB VRAM

512 by 384 8, 16, 32 8, 16, 32

640 by 480 8, 16, 32 8, 16, 32

768 by 576 8, 16, 32 8, 16, 32

800 by 600 8, 16, 32 8, 16, 32

832 by 624 8, 16, 32 8, 16, 32

1024 by 768 8, 16 8, 16, 32

1152 by 870 8, 16 8, 16

Specifications Video Support - 9

Table 1: PM8500 and WS 8550 Video Support

PIXEL DEPTHS

MONITOR DISPLAY SIZE 2 MB VRAM 4 MB VRAM

1280 by 960 8 8, 16

1280 by 1024 8 8, 16

Specifications Disk Storage - 10

Disk Storage

Hard Drive

PM 8500

WS 8550

Floppy Drive

CD-ROM Drive

1, 1.2, or 2 GB fast internal SCSI hard drive

2 GB fast internal SCSI hard drive
Supports drive array with dual hard drive bracket

One Apple SuperDrive 1.4 MB floppy drive

One internal AppleCD 600i 4x CD-ROM drive or

1200i 8x CD-ROM drive

Specifications Electrical - 11

Electrical

Line V oltage

Frequency

Maximum Power

100—240 VAC, RMS single phase, automatically configured

50—60 Hz, single phase

DC Power: 225 W, not including monitor
AC Power: 340 W maximum continuous; 520 W peak input

Specifications Physical - 12

Physical

Dimensions

Weight

Height: 14 in. (35.6 cm)
Width: 7.7 in. (19.6 cm)
Depth: 15.75 in. (40.0 cm)

25 lb. (11.3 kg); weight varies depending on devices installed

Specifications Environmental - 13

Environmental

Operating Temperature

Storage Temperature

Relative Humidity

Maximum Altitude

50 to 104° F (10 to 40° C)

—40 to 116° F (—40 to 47° C)

5% to 95% noncondensing

10,000 ft. (3,048 m)

K

Service Source

Troubleshooting

Power Macintosh 8200 and 8500

Series/WS 8550 Series

Troubleshooting General - 1

General

The Symptom Charts included in this chapter will help you
diagnose specific symptoms related to your product. Because cures
are listed on the charts in the order of most likely solution, try
the first cure first. Verify whether or not the product continues to
exhibit the symptom. If the symptom persists, try the next cure.
(Note: If you have replaced a module, reinstall the original module
before you proceed to the next cure.)

If you are not sure what the problem is, or if the Symptom Charts
do not resolve the problem, refer to the Flowchart for the product
family.

For additional assistance, contact Apple Technical Support.

Troubleshooting Cleaning Procedure for Card Connectors - 2

Cleaning Procedure for Card Connectors

It is possible for residue to build up on the gold edge connector
pins on some PCI cards, which could cause a variety of symptoms.

If you are having problems with a PCI card, inspect the connector
pins with a magnifying glass. If you find residue, use a pencil
eraser to gently clean the pins.

Troubleshooting Symptom Charts/Power Supply - 3

Symptom Charts

Power Supply

System doesn’t power up1 Reseat processor card and ROM SIMM (if present).

2 Reset Cuda chip. (Refer to The Cuda Chip in Basics for

instructions.)

3 Reset logic board. (Refer to Resetting the Logic Board in

Basics for instructions.)
4 Replace power supply.
5 Replace processor card.
6 Replace logic board.

Troubleshooting Symptom Charts/Error Chords - 4

Error Chords

One-part error
chord sounds during
startup sequence

1 Disconnect SCSI data cable from hard drive and reboot

system. If startup sequence is normal, initialize hard drive.

Test unit again with SCSI data cable connected. If error chord

still sounds, replace hard drive.
2 Disconnect floppy drive cable from floppy drive and reboot

system. If startup sequence is normal, replace floppy drive.
3 Reseat processor card.
4 Replace processor card.
5 Replace logic board. Retain customer's DIMMs.

Troubleshooting Symptom Charts/Error Chords

(Continued)

- 5

Eight-part error
chord (death chimes)
sounds during
startup sequence

Error Chords

1 Replace DRAM DIMMs one at a time to test DRAM. Replace

any faulty DIMMs.
2 Replace logic board.

(Continued)

Troubleshooting Symptom Charts/System - 6

System

Does not power on,
screen is black, fan is
not running and LED
is not lit

1 Check power cables.
2 Plug monitor directly into wall socket, and verify that

monitor has power.
3 Reseat ROM SIMM (if present) and processor card. The logic

board must have a processor card installed to operate.
4 Reset Cuda chip. (Refer to The Cuda Chip in Basics for

instructions.)
5 Reset logic board. (Refer to Resetting the Logic Board in

Basics for instructions.)
6 Replace power cord.
7 Replace power supply.
8 Replace processor card.
9 Replace logic board. Retain customer's DIMMs.

Troubleshooting Symptom Charts/System

(Continued)

- 7

Clicking, chirping,
or thumping

System

1 Remove all PCI cards and test the unit. If problem does not

2 Remove hard drive. If problem no longer occurs, replace

3 Replace power supply.
4 Replace processor card.
5 Replace logic board. Retain customer's DIMMs.
6 Replace floppy drive cable.
7 Replace floppy drive.

(Continued)

occur with cards removed, begin replacing them one at a

time to determine which card is causing the problem.

Replace problem card with known-good card.

hard drive with a known-good drive.

Troubleshooting Symptom Charts/System

(Continued)

- 8

System shuts down
intermittently

System

1 Make sure air vents are clear. Thermal protection

2 Make sure power cord is firmly plugged in.
3 Replace power cord.
4 Check battery.
5 Reset Cuda chip. (Refer to The Cuda Chip in Basics for

6 Reset logic board. (Refer to Resetting the Logic Board in

7 Replace power supply.
8 Replace processor card.
9 Replace logic board. Retain customer's DIMMs.

(Continued)

circuitry may shut down system. After 30 to 40 minutes,

system should be OK.

instructions.)

Basics for instructions.)

Troubleshooting Symptom Charts/System

(Continued)

- 9

System
intermittently
crashes or hangs

System

1 Verify system software is version 7.5.2 or later (PM8500/

2 Verify DIMMs are noncomposite.
3 Verify software is known-good. Do a clean install of the

4 Verify software is Power Macintosh 8500 compatible

5 Clear parameter RAM. Hold down <Command> <Option> <P>

6 Remove all DRAM DIMMs and try replacing them one at a

7 Replace processor card.
8 Replace logic board. Retain DIMMs.

(Continued)

120) or 7.5.3 or later (PM 8500/132, PM 8500/150,

and WS 8550).

system software.

(contact developer). Also, try booting with extensions off to

determine if there are system init problems.

<R> during startup but before "Welcome to Macintosh"

appears.

time to test. Replace any bad DIMMs.

Troubleshooting Symptom Charts/System

(Continued)

- 10

During startup,
following message is
displayed, "This
startup disk will not
work on this

Macintosh model...."

PM 8200 can’t be
powered off unless
external 1.2 GB hard
drive is off
remains lit when
system is powered off
and attached 1.2 GB
hard drive is left
powered on

or

LED

System

1 Verify that startup disk is good.
2 Verify system software is version 7.5.2 or later (PM8500/

3 Do a clean install of the system software.

This problem only affects PM 8200 machines with serial
numbers in the following ranges:

(Continued)

120) or 7.5.3 or later (PM 8500/132, PM 8500/150,

and WS 8550).

• CK634xxxxxx to CK637xxxxxx

• XB634xxxxxx to XB637xxxxxx

• SG634xxxxxx to SG637xxxxxx

• FC634xxxxxxx to FC637xxxxxx

•
If system falls into one of these serial number ranges, execute
the following instructions:

Troubleshooting Symptom Charts/System

1) Unplug system and remove top cover.

2) Disconnect hard drive SCSI cable and power cable.

3) Remove hard drive from chassis.

4) Turn drive over and examine part number label on 50-pin
SCSI connector (removing drive carrier if necessary). If
label reads “1280S p/n TM12S012”
replace drive.

Note

: Only Revision “02” drives cause this problem; there­fore, make sure bar code label includes the words “REV 02­B” before replacing hard drive.

and

“REV 02-B”,

(Continued)

- 11

Troubleshooting Symptom Charts/Video - 12

Video

Screen is black, boot
tone is present, drive
operates, fan is
running, and LED is
lit

1 Adjust brightness on monitor.
2 Clear parameter RAM. Hold down <Command> <Option> <P>

<R> during startup but before "Welcome to Macintosh"

appears.
3 Reset Cuda chip. (Refer to The Cuda Chip in Basics.)
4 Reset logic board. (Refer to Resetting the Logic Board in

Basics.)
5 Replace monitor cable.
6 Remove all DRAM DIMMs and try replacing them one at a

time to test. Replace any bad DIMMs.
7 Test with known-good monitor. Replace monitor if

necessary. Refer to appropriate monitor manual to

troubleshoot defective monitor.
8 Replace processor card.
9 Replace logic board. Retain customer's DIMMs.

Troubleshooting Symptom Charts/Video

(Continued)

- 13

Screen is black, no
boot tone and drive
does not operate, but
fan is running and
LED is lit

Video

1 Reset Cuda chip. (Refer to The Cuda Chip in Basics for

2 Reset logic board. (Refer to Resetting the Logic Board in

3 Remove all DRAM DIMMs and try replacing them one at a

4 Replace processor card.
5 Replace logic board. Retain customer's DIMMs.
6 Replace power supply.

(Continued)

instructions.)

Basics for instructions.)

time to test. Replace any bad DIMMs.

Troubleshooting Symptom Charts/Video

(Continued)

- 14

Boot tone is present
and screen lights up,
but nothing is
displayed on screen

Video

1 Reset Cuda chip. (Refer to The Cuda Chip in Basics for

2 Reset logic board. (Refer to Resetting the Logic Board in

3 Replace monitor cable.
4 Test with known-good monitor. Replace monitor if

5 Replace processor card.
6 Replace logic board. Retain customer's DIMMs.

(Continued)

instructions.)

Basics for instructions.)

necessary. Refer to appropriate monitor manual to

troubleshoot defective monitor.

Troubleshooting Symptom Charts/Video

(Continued)

- 15

Video display
distorted on Power
Macintosh 8500 with
DAV card installed

Video

Symptom occurs when an add-in card attached to the DAV
connector requires a mode configuration under which the add-in
card controls most of the signal lines (Mode 2). Verify that the
logic board installed supports DAV cards; if not, replace the logic
board.

If the logic board in question meets
then it DOES support DAV cards and you need not replace the board:

(Continued)

either

of the following criteria,

• Part number 820-0752 is silk-screened on the logic
board.

• The Logic board has the wiring scenario shown on the next
page.

Troubleshooting Symptom Charts/Video

NOTE: The dotted
line indicates that
the jumper wire is
running underneath
the logic board.

(Continued)

- 16

Jumper Wire

PCB Part Number

Power Macintosh 8500 Logic Board with DAV Fix

U18

820-0564-XX

Troubleshooting Symptom Charts/Floppy Drive - 17

Floppy Drive

Internal floppy drive
does not operate

During system
startup, disk ejects;
display shows icon
with blinking "X"

1 Replace floppy disk with known-good disk.
2 Replace floppy drive cable.
3 Replace floppy drive.
4 Replace processor card.
5 Replace logic board. Retain customer's DIMMs.

1 Replace disk with known-good system disk.
2 Replace floppy drive cable.
3 Replace floppy drive.
4 Replace processor card.
5 Replace logic board. Retain customer's DIMMs.

Troubleshooting Symptom Charts/Floppy Drive

(Continued)

- 18

Floppy Drive

Does not eject disk 1 Switch off computer. Hold mouse button down while you

switch computer on.
2 Replace floppy drive cable.
3 Replace floppy drive.
4 Replace processor card.
5 Replace logic board. Retain customer's DIMMs.

Attempts to eject
disk, but doesn’t

1 Reseat floppy drive bezel and drive so bezel slot aligns

correctly with drive.
2 Replace floppy drive.

(Continued)

Troubleshooting Symptom Charts/Floppy Drive

(Continued)

- 19

Internal floppy drive
runs continuously

MS-DOS drive does
not recognize a disk
formatted on a 1.4 MB
drive

Floppy Drive

1 Replace disk with known-good floppy disk.
2 Replace floppy drive cable.
3 Replace floppy drive.
4 Replace processor card.
5 Replace logic board. Retain customer's DIMMs.

To read and write files with either MS-DOS or 1.4 MB drive,
format all disks with MS-DOS drive first.

(Continued)

Troubleshooting Symptom Charts/Hard Drive - 20

Hard Drive

Single internal hard
drive does not
operate; drive
doesn’t spin

No internal SCSI
drives operate

1 Replace hard drive power cable.
2 Replace hard drive. If problem resolved, reinstall SCSI

device driver and system software.
3 Replace power supply.

1 Verify there are no duplicate SCSI device addresses.
2 Disconnect external SCSI devices and check for proper

termination. Only last device in SCSI chain should be

terminated.
3 Replace SCSI data cable.
4 Replace power supply.
5 Replace processor card.
6 Replace logic board. Retain customer's DIMMs.

Troubleshooting Symptom Charts/Hard Drive

(Continued)

- 21

Drive does not appear
on the desktop

Hard Drive

1 Verify there are no duplicate SCSI device addresses.
2 Update the SCSI device driver using Drive Setup. Run Disk

First Aid to verify the condition of the drive's directory

structure.
3 Replace the SCSI hard drive cable.
4 If drive is not initialized, use Drive Setup to initialize.
5 Replace with known-good hard drive.
6 If the hard drive still doesn't work, switch back to the

original hard drive and replace the logic board.

(Continued)

Troubleshooting Symptom Charts/Hard Drive

(Continued)

- 22

Works with internal
or external SCSI
devices but not with
both

Hard Drive

1 Verify there are no duplicate SCSI device addresses.
2 Replace terminator on external SCSI device.
3 Verify that SCSI device at end of internal SCSI data cable is

only device terminated.
4 Refer to appropriate manual to troubleshoot defective

external device.

(Continued)

Troubleshooting Symptom Charts/Peripherals - 23

Peripherals

Cursor does not move 1 Check mouse connection.

2 Inspect inside of mouse for buildup of dirt or other

contaminants. Clean mouse if necessary.
3 If mouse was connected to keyboard, connect mouse to

computer ADB port instead. If mouse works, replace

keyboard.
4 Replace ADB cable.
5 If mouse does not work in any ADB port on computer, replace

mouse.
6 Replace processor card.
7 Replace logic board. Retain customer's DIMMs.

Troubleshooting Symptom Charts/Peripherals

(Continued)

- 24

Cursor moves, but
clicking mouse
button has no effect

Double-click doesn’t
open application,
disk, or server

Peripherals

1 Boot from floppy or bootable CD.
2 Replace mouse.
3 Replace logic board. Retain customer's DIMMs.

1 Remove duplicate system folders.
2 Clear parameter RAM. Hold down <Command> <Option> <P>

<R> during startup but before "Welcome to Macintosh"

appears.
3 If mouse was connected to keyboard, connect mouse to

computer ADB port instead. If mouse works, replace

keyboard.
4 If mouse does not work in any ADB port on computer, replace

mouse.
5 Replace logic board. Retain customer's DIMMs.

(Continued)

Troubleshooting Symptom Charts/Peripherals

(Continued)

- 25

No response to any
key on keyboard

Known-good serial
printer does not work

Peripherals

1 Check keyboard connection to ADB port.
2 Replace keyboard cable.
3 Replace keyboard.
4 Replace logic board. Retain customer's DIMMs.

1 Verify you have correct version of system software.
2 Verify that Chooser is set correctly.
3 Reinstall correct printer drivers.
4 Do clean install of system software.
5 Replace printer interface cable.
6 Replace logic board. Retain customer's DIMMs.

(Continued)

Troubleshooting Symptom Charts/Peripherals

(Continued)

- 26

Known-good network
printer does not print

Peripherals

1 Check network connections.
2 Verify you have correct version of system software.
3 Verify that Chooser is set correctly.
4 Does printer show up in Chooser? If so, do clean install of

system software and/or network and printer software.
5 Replace logic board. Retain customer's DIMMs.

(Continued)

Troubleshooting Symptom Charts/CD-ROM Drive - 27

CD-ROM Drive

CD-ROM drive does
not work

Macintosh does not
display CD-ROM icon
once CD is inserted in
drive

Computer with 600i
CD-ROM drive makes
stuttering sounds
when playing CD+ or
CD-R formatted
discs or CD-ROM disc
won’t mount

1 Try using known-good compact disc.
2 Replace CD-ROM drive mechanism.

1 Verify that CD-ROM software is installed.
2 Replace CD-ROM drive mechanism.
3 Replace SCSI data cable.

Replace CD-ROM drive.

Troubleshooting Symptom Charts/Miscellaneous - 28

Miscellaneous

No sound from
speaker

1 Verify that volume setting in Control Panel is 1 or above.
2 Clear parameter RAM. Hold down <Command> <Option> <P>

<R> during startup but before "Welcome to Macintosh"

appears. Verify speaker is plugged into logic board.
3 Replace speaker.
4 Replace logic board. Retain customer’s DIMMs.

Troubleshooting Symptom Charts/Miscellaneous - 29

Errors occur when
initializing or erasing
floppy disks and/or

1.4 MB disks show
only 1 MB available
after initialization

This problem only occurs on systems using a 180 MHz or faster
processor card. Upgrade to system software version 7.5.4 to
resolve this problem (the Apple recommended solution) or,
alternatively, install the Power Mac Format Patch, which can be
found on the original system disks that shipped with the computer.
To install the patch:

• While holding down the Option key, drag the Power Mac
Format Patch icon onto the System Folder’s icon.

• Click OK to automatically place the patch in the Extensions
folder.

• Restart the computer by choosing Restart from the Special
menu.

K

Service Source

T ak e Apart

Power Macintosh 8500 Series/WS

8550 Series

Take Apart Top Housing - 1

Top Housing

Top Housing

No preliminary steps are
required before you begin
this procedure.

Note:

The top housing covers
the top, front, and left and
right sides of the computer.

IMPORTANT

the computer with the top
housing removed. Failure to
comply may result in
irreparable damage to
internal components.

: Never operate

Take Apart Top Housing - 2

1 Loosen the four captive

cover screws on the rear
panel and slide the top
housing forward about

1

3

2

4

one inch.

Take Apart Top Housing - 3

2 Lift the top housing

Top Housing

straight up to remove it
from the computer.

Take Apart CD-ROM Drive - 4

CD-ROM
Drive

CD-ROM Drive

Before you begin, remove
the top housing.

Note:

The CD-ROM drive is

located in the top drive bay.

Take Apart CD-ROM Drive - 5

CD-Rom Audio Cable




CD-Rom Drive

Power CableSCSI Data Cable

1 Disconnect the SCSI data

cable, audio cable, and
power cable from the
back of the CD-ROM
drive.

Take Apart CD-ROM Drive - 6

Retaining ClipCD-ROM Drive

2 Pull up the retaining

clip beneath the front of
the CD-ROM drive and
slide the drive forward
to remove it from the
computer.

Note:

Be sure to remove the
CD-ROM drive from its
carrier before returning the
drive to Apple.

Take Apart Floppy Drive - 7

Floppy

Floppy
Drive

Drive

Floppy Drive

Before you begin, remove
the following:

• Top Housing

• CD-ROM Drive

Note:

The floppy drive is
located in the second drive
bay from the top.

Take Apart Floppy Drive - 8

Floppy Drive

Plastic Guides

Floppy Drive Cable

1 Disconnect the floppy

drive cable from the
logic board and remove
the cable from the
plastic guides.

Take Apart Floppy Drive - 9

Floppy Drive Retaining Clip

2 Press down the retaining

clip beneath the front of
the floppy drive and
slide the floppy drive
forward about two
inches.

3 Disconnect the floppy

drive cable from the
back of the floppy drive
and remove the floppy
drive from the
computer.

Replacement Note:

Be sure
to remove the floppy drive
from its carrier before
returning the drive to Apple.

Take Apart DAT Tape Drive-WS 8550 - 10

DAT Tape Drive­WS 8550

Before you begin, remove
the top housing.

Note:

The DAT tape drive is
located in third drive bay
from the top. The tape drive
is optional on the WS 8550.

Take Apart DAT Tape Drive-WS 8550 - 11

1 Disconnect the SCSI

cable and power cable
from the back of the tape
drive.

Take Apart DAT Tape Drive-WS 8550 - 12

2 Remove the four screws

securing the carrier to
the tape drive. Remove
the carrier before
returning the tape drive
to Apple.

Take Apart Hard Drive-Power Macintosh 8500 - 13

Hard Drive-Power Macintosh 8500

Before you begin, remove
the top housing.

Note:

The hard drive is
located in the bottom drive

Hard
Drive

bay.

Take Apart Hard Drive-Power Macintosh 8500 - 14

1 Disconnect the SCSI data

cable and hard drive
power cable from the
hard drive.

Power CableSCSI Cable

Take Apart Hard Drive-Power Macintosh 8500 - 15

2 Press down the retaining

clip beneath the front of
the hard drive and slide
the hard drive forward
to remove it from the
computer.

Note:

For information on
removing the hard drive
from its carrier and
returning drives, cables,
and carriers to Apple, refer
to Additional Procedures in
the Hard Drives manual.

Hard Drive Retaining Clip

Take Apart Hard Drive-WS 8550 - 16

Hard Drive-WS 8550

Before you begin, remove
the top housing.

Note:

The Workgroup
Server 8550 can hold up to
two hard drives, which
install in a metal drive
bracket as opposed to the
plastic drive carrier used in
the Power Macintosh 8500.

Take Apart Hard Drive-WS 8550 - 17

1 Press down the retaining

clip beneath the front of
the hard drive bracket
and gently slide the hard
drive bracket forward as
far as it will reach.

Take Apart Hard Drive-WS 8550 - 18

2 Disconnect the SCSI

cable from the back of
the hard drive.