Apple Macintosh IIfx Service Manual

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Macintosh II/IIx/IIfx

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Basics

Macintosh II/IIx/IIfx

Basics Overview - 1

Overview

This manual includes
complete repair procedures
for the Macintosh II,
Macintosh IIx, and
Macintosh IIfx.

Figure: Macintosh II, IIx, IIfx

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Specifications

Macintosh II/IIx/IIfx

Specifications Processor - 1

Processor

CPU

Macintosh II

Macintosh IIx

Macintosh IIfx

Motorola 68020 microprocessor

15.6772 MHz
Optional built-in paged memory management unit (PMMU)

Motorola 68030 microprocessor

15.6772 MHz
Built-in paged memory management unit (PMMU)

Motorola 68030 microprocessor
40 MHz
Built-in paged memory management unit (PMMU)

Specifications Processor - 2

Coprocessor

Macintosh II

Macintosh IIx/IIfx

Addressing

Motorola 68881 math coprocessor

Motorola 68882 math coprocessor

32-bit registers
32-bit address bus
32-bit data bus

Specifications Memory - 3

Memory

RAM

Macintosh II/IIx

Macintosh IIfx

ROM

Macintosh II/IIx

Macintosh IIfx

1 MB, expandable to 8 MB

4 MB standard, expandable to 8 MB

256K

512K

Specifications Disk Storage - 4

Disk Storage

Floppy Drive

Macintosh II

Macintosh IIx/IIfx

Hard Drive

Internal 800K floppy drive
Optional second internal 800K floppy drive
Optional internal 1.4 MB floppy drive upgrade

Internal 1.4 MB floppy drive
Optional second internal 1.4 MB floppy drive

Optional internal 40, 80, or 160 MB hard drive

Specifications I/O Interfaces - 5

I/O Interfaces

Expansion

SCSI

Apple Desktop Bus

Serial

NuBus

Processor-direct slot (PDS)

5 MB/sec. transfer rate
Eight device maximum

Two ADB ports allow daisy-chaining of peripheral devices

Two RS-232/RS-422 serial ports; mini DIN-8 connectors

Six internal NuBus slots support full 32-bit address and data

buses

Specifications Sound and Video - 6

Sound and Video

Sound Generator

Apple’s custom digital sound chip provides 8-bit stereo sampling

at 44.1 kHz and includes four-voice, wavetable synthesis;
capable of driving stereo headphones or other stereo equipment
through the sound jack.

Specifications Electrical - 7

Electrical

Line V oltage

Frequency

Maximum Power

Macintosh II/IIx

Macintosh IIfx

100–240 VAC, automatically configured

48–62 Hz, single phase

220 W (not including monitor power)

230 W (not including monitor power)

Specifications Physical - 8

Physical

Dimensions

Weight

Height: 5.5 in. (14.0 cm)
Width: 18.7 in. (47.4 cm)
Depth: 14.4 in. (36.5 cm)

24 lb. (10.9 kg)
Weight will be greater with internal hard drive.

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Troubleshooting

Macintosh II/IIx/IIfx

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 Symptom Charts/Error Chord - 2

Symptom Charts

Error Chord

Error chord sounds
during startup
sequence

1 Perform SIMM verification on customer’s logic board.

Replace Apple-labeled SIMMs manufactured by NEC that have
date code of 9052 or below.

2 Replace logic board. Retain customer’s SIMMs.

Troubleshooting Symptom Charts/System - 3

System

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

Clicking, chirping,
or thumping

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

monitor has power.
3 Replace power cord.
4 Check batteries. Refer to “Battery Verification” in

Additional Procedures.
5 Replace power supply.
6 Replace logic board. Retain customer’s SIMMs.

1 Remove additional NuBus cards.
2 Replace power supply.
3 Replace logic board. Retain customer’s SIMMs.

Troubleshooting Symptom Charts/System

(Continued)

- 4

System shuts down
intermittently

System
intermittently
crashes or locks

System

1 Make sure air vents on sides and top of case are

2 Replace power cord.
3 Check batteries. Refer to “Battery Verification” in

4 Replace power supply.
5 Replace logic board. Retain customer’s SIMMs.

1 Make sure system software is correct version.
2 Make sure software is known-good.
3 Remove additional RAM and NuBus cards.
4 Replace logic board. Retain customer’s SIMMs.
5 Replace SIMMs.
6 Replace power supply.

(Continued)

unobstructed. Thermal protection circuitry may shut down

system. After 30–40 minutes, system should be OK.

Additional Procedures.

Troubleshooting Symptom Charts/System

(Continued)

- 5

System

System doesn’t boot Replace Apple-labeled SIMMs manufactured by NEC that have date

code of 9052 or below.

(Continued)

Troubleshooting Symptom Charts/Video - 6

Video

Screen is black, audio
and drive operate, fan
is running, and LED is
lit

1 Adjust brightness on monitor.
2 Verify monitor works with another Macintosh.
3 Replace monitor. Refer to appropriate monitor manual to

troubleshoot defective monitor.
4 Replace video cable.
5 Move video card to different slot.
6 Replace video card. Refer to Video Cards manual.
7 Replace SIMMs.
8 Replace logic board. Retain customer’s SIMMs.
9 Replace power supply.

Troubleshooting Symptom Charts/Video

(Continued)

- 7

Screen is black, audio
and drive do not
operate, but fan is
running and LED is lit

Video

1 Replace video cable.
2 Move video card to different slot.
3 Verify monitor works with another Macintosh.
4 Replace video card. Refer to Video Cards manual.
5 Replace SIMMs.
6 Replace logic board. Retain customer’s SIMMs.
7 Replace power supply.
8 Replace monitor. Refer to appropriate monitor manual to

(Continued)

troubleshoot defective monitor.

Troubleshooting Symptom Charts/Video

(Continued)

- 8

Screen is completely
dark, fan is not
running, and LED is
not lit

Video display
exhibits ghosting

System boots and then
loses video

Video

1 Plug monitor directly into wall socket, and verify that

2 Check batteries. Refer to “Battery Verification” in

3 Replace power supply.
4 Replace logic board. Retain customer’s SIMMs.

Replace Apple-labeled SIMMs manufactured by NEC that have date
code of 9052 or below.

Replace Apple-labeled SIMMs manufactured by NEC that have date
code of 9052 or below.

(Continued)

monitor has power.

Additional Procedures.

Troubleshooting Symptom Charts/Video

(Continued)

- 9

Partial or whole
screen is bright and
audio is present, but
no video information
is visible

Video

1 Verify monitor works with another Macintosh.
2 Replace monitor. Refer to appropriate monitor manual to

3 Replace video cable.
4 Move video card to different slot.
5 Replace video card. Refer to Video Cards manual.
6 Replace logic board. Retain customer’s SIMMs.

(Continued)

troubleshoot defective monitor.

Troubleshooting Symptom Charts/Floppy Drive - 10

Floppy Drive

Internal floppy drive
runs continuously

Audio and video are
present, but one
internal floppy drive
does not operate

1 Replace bad disk.
2 Replace internal floppy drive cable.
3 Replace internal floppy drive.
4 Replace logic board. Retain customer’s SIMMs.

1 Replace bad disk.
2 Verify that all external SCSI devices are disconnected.
3 Replace internal floppy drive cable.
4 Replace internal floppy drive.
5 Replace logic board. Retain customer’s SIMMs.
6 Replace power supply.

Troubleshooting Symptom Charts/Floppy Drive

(Continued)

- 11

Floppy Drive

Audio and video are
present, but neither
internal floppy drive
operates

Disk ejects; display
shows icon with
blinking “X”

Will not eject disk 1 Switch power off and hold mouse button down while

1 Replace bad disk.
2 Verify that all external SCSI devices are disconnected.
3 Replace logic board. Retain customer’s SIMMs.
4 Replace power supply.

1 Replace disk with known-good system disk.
2 Replace internal floppy drive cable.
3 Replace internal floppy drive.
4 Replace logic board. Retain customer’s SIMMs.

switching power back on.
2 Replace internal floppy drive.

(Continued)

Troubleshooting Symptom Charts/Floppy Drive

(Continued)

- 12

Attempts to eject disk
but doesn’t

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

Floppy Drive

1 Reinsert disk.
2 Reseat top cover so drive slots align correctly.

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 - 13

Hard Drive

Internal hard drive
will not operate; LED
doesn’t light; drive
doesn’t spin

Works with internal
hard drive or
external SCSI device
but not with both

1 Remove hard drive data cable.
2 Replace internal hard drive power cable.
3 Verify +5V and 12V lines to hard drive.
4 Replace internal hard drive.
5 Replace logic board. Retain customer’s SIMMs.

1 Verify that SCSI device switch setting on external device

isn’t 0 (internal hard drive address) or 7 (computer

address).
2 Verify proper SCSI termination. Refer to “SCSI

Termination” in Additional Procedures.
3 Replace SCSI terminator on external device.
4 Troubleshoot external SCSI device.

Troubleshooting Symptom Charts/Hard Drive

(Continued)

- 14

Drive icon does not
appear on desktop

Data is lost or
corrupted

Hard Drive

Verify proper SCSI termination. Refer to “SCSI Termination” in
Additional Procedures.

Verify proper SCSI termination. Refer to “SCSI Termination” in
Additional Procedures.

(Continued)