Apple Macintosh Quadra Centris 650 Service Manual

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Service Source

Centris 650/Quadra 650

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Service Source

Basics

Centris 650/Quadra 650

Basics Overview - 1

Overview

This manual includes
complete repair procedures
for the Macintosh Centris
650/Quadra 650 shown at
left.

Figure: Macintosh Centris 650/Quadra 650

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Service Source

Specifications

Centris 650/Quadra 650

Specifications Processors - 1

Processors

Centris 650

Quadra 650

Coprocessor

Addressing

Motorola 68040
25 MHz
Built-in memory management unit (MMU)

Motorola 68040
33 MHz
Built-in memory management unit (MMU)

Optional floating-point unit (FPU)

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

Specifications Memory - 2

Memory

RAM

ROM

PRAM

VRAM

Clock/calendar

4 or 8 MB RAM, expandable to 132 MB (72-pin SIMM)

1 MB

256 bytes nonvolatile parameter memory

512K, expandable to 1 MB

CMOS custom chip with long-life lithium battery

Specifications Disk Storage - 3

Disk Storage

Floppy Drive

Hard Drive

CD-ROM

1.4 MB Apple SuperDrive

Internal Apple SCSI hard drive
80 MB to 500 MB

Optional internal 5.25-in. CD-ROM drive

Specifications I/O Interfaces - 4

I/O Interfaces

SCSI

Apple Desktop Bus

Serial

NuBus

One SCSI port; DB-25 connector
Supports a maximum of six external devices (internal SCSI
devices include the computer, which is always device 7)

Two Apple Desktop Bus (ADB) ports; mini-Din-4 connectors
Low-speed synchronous serial interface

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

230.4 Kbps maximum

0.92 Mbps maximum, clocked externally

Three NuBus slots

Specifications I/O Interfaces - 5

Expansion Slot

Sound

Video

Ethernet

One inline processor-direct slot

One stereo-capable output port
One monaural input port

One video port, DB-15 connector
Supports Apple monitors (8-bit)
VGA and SVGA monitors require a special adapter cable

On-board Apple Ethernet port

Specifications I/O Devices - 6

I/O Devices

Keyboard

Mouse

Microphone

Standard, extended, or adjustable keyboard connected through two

ADB ports
Maximum power draw for all ADB devices: 500 mA
Keyboard draws 25–80 mA

ADB Mouse II; mechanical tracking optical shaft or contact
encoding (low power)

Optional electret, omnidirectional microphone
Microphone output voltage is 4 mV peak to peak at normal value
Mini phone plug connector

Specifications Sound and Video - 7

Sound and Video

Video Display

Centris 650/Quadra 650 supports these Apple monitors:

• Macintosh 12” Monochrome Display

• Macintosh 12” RGB Display

• AppleColor High-Res RGB 13” Monitor

• Macintosh Color Display

• Macintosh 15” Portrait Display

• Macintosh 16” Color Display

• Apple Two-Page 21” Monochrome Monitor

• Macintosh 21” Color Display
Supports NTSC and PAL
Supports VGA monitors (640 pixels by 480 pixels only) and
SVGA monitors (800 pixels by 600 pixels only) with
appropriate adapter cable

Specifications Sound and Video - 8

Sound

Custom sound chip supports stereo playback from compact discs
and computer-generated stereo sounds through stereo output port
Monaural sound input port

Specifications Electrical - 9

Electrical

Line V oltage

Frequency

100–240 VAC

50–60 Hz
112 W maximum, not including display power

Specifications Physical - 10

Physical

Dimensions

Height: 6.0 in. (152 mm)
Width: 13.0 in. (330 mm)
Depth: 16.5 in. (419 mm)
Weight
25 lb. (11.3 kg)
Weight will vary based on internal devices installed.

Specifications Environmental - 11

Environmental

Operating Temperature

Storage Temperature

Relative Humidity

Altitude

50–104°F (10–40°C)

–40F to 116.6°F (–40 to 47°C)

10–90% RH (noncondensing)

0–10,000 ft. (3,048 m)

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Service Source

Troubleshooting

Centris 650/Quadra 650

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 Chords - 2

Symptom Charts

Error Chords

One-part error
chord sounds during
startup sequence

1 Disconnect hard drive power cable and hard drive data cable.

Reboot system. If startup sequence is normal, run Macintosh
Hard Disk test and replace hard drive if necessary.

2 Disconnect floppy drive cable and reboot system. If startup

sequence is normal, replace floppy drive.

3 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 Replace power supply.
5 Replace logic board.

1 Replace power supply.
2 Replace logic board. Retain customer’s SIMMs.

Troubleshooting Symptom Charts/System

(Continued)

- 4

System shuts down
intermittently

System
intermittently
crashes or locks up.

System

1 Check that air vents are clear. Thermal protection circuitry

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 Verify that system software is correct version.
2 Disconnect external SCSI devices.
3 Verify that software is known-good.
4 Replace SIMMs. (Refer to Hardware/Memory.)
5 Replace power supply.
6 Replace logic board. Retain customer’s SIMMs

(Continued)

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

should be OK.

Additional Procedures.

Troubleshooting Symptom Charts/

System (Continued)

- 5

Does not start up with
out a monitor attached

System

Verify that the Chooser and Control Panels are set correctly.

(Continued)

Troubleshooting Symptom Charts/Video - 6

Video

Screen is dark, audio
and at least one drive
operate, fan is
running, and LED is
lit

Screen is dark, audio
and drive do not
operate, 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 Mac appears.
3 Check cables.
4 Replace monitor. Refer to appropriate monitor manual to

troubleshoot defective monitor.
5 Replace video card.
6 Replace VRAM SIMMs.
7 Replace logic board. Retain customer’s SIMMs.

1 Remove peripherals.
2 Remove NuBus cards.
3 Replace DRAM SIMMs.
4 Replace VRAM SIMMs.
5 Replace power supply.
6 Replace logic board.

Troubleshooting Symptom Charts/Video

(Continued)

- 7

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

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

Video

1 Check cables
2 Clear parameter RAM. Hold down <Command> <Option>

3 Replace monitor. Refer to appropriate monitor manual to

4 Replace video cable.
5 Replace VRAM SIMMs.
6 Replace logic board. Retain customer’s SIMMs.

1 Verify that external power cables are properly connected.
2 Remove peripherals.
3 Remove NuBus cards.
4 Replace power supply.
5 Replace logic board. Retain customer’s SIMMs.

(Continued)

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

appears.

troubleshoot defective monitor.

Troubleshooting Symptom Charts/Floppy Drive - 8

Floppy Drive

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

Floppy disk ejects,
and display shows Mac
icon with blinking
“X”

Floppy disk does not
eject

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

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

1 Switch off system and hold mouse button down while

switching on.
2 Eject disk manually.
3 Replace floppy drive cable.
4 Replace floppy drive.

Troubleshooting Symptom Charts/Floppy Drive

(Continued)

- 9

Floppy drive
attempts to eject disk
but doesn’t

Floppy Drive

1 Push floppy disk completely in.
2 Eject floppy disk manually.
3 Replace floppy drive.

(Continued)