Apple Macintosh Quadra Centris AWS95 Service Manual

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Macintosh Quadra 900/950/

AWS 95

Macintosh Quadra 900, Macintosh Quadra 950, Apple

Workgroup Server 95

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Basics

Macintosh Quadra 900/950/AWS 95

Basics	Overview - 2

Overview

This manual includes complete repair procedures for the Quadra 900/950 and the Apple Workgroup Server 95, pictured at left.

Figure: Macintosh Quadra 900/950 and AWS 95

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Specifications

Macintosh Quadra 900/950/AWS 95

	Specifications	Processor - 1
		Processor
CPU		Motorola 68040 microprocessor
		Built-in paged memory management unit (PMMU), floating-point
		unit (FPU), and 8K memory cache
Quadra 900:		25 MHz
Quadra 950 and AWS		33 MHz
95:
Addressing		32-bit registers
		32-bit address bus
		32-bit data bus

Specifications	Memory - 2

Memory

RAM

Quadra 900

Quadra 950

AWS 95

ROM

PRAM

4 MB standard, expandable to 256 MB (80 ns or faster SIMMs)

8 MB standard, expandable to 256 MB (80 ns or faster SIMMs)

16 MB, 32 MB, or 48 MB parity RAM standard, expandable to 256 MB (80 ns or faster 9-bit SIMMs)

1 MB, using two 150 ns, 256K by 16-bit chips

256 bytes of parameter memory

	Specifications	Memory - 3
VRAM		1 MB, expandable to 2 MB (100 ns or faster VRAM SIMMs) by
		installing four 256K or two 512K SIMMs
Clock/Calendar		ASIC clock chip with PRAM and DFAC support and seven-year
		lithium battery

Specifications	Disk Storage - 4

Floppy Drive

Hard Drive

Quadra 900 and 950

AWS 95

Disk Storage

Internal, 1.4 MB Apple SuperDrive

230, 500, or 1000 MB hard drive (optional)

230, 500, 1000, or 2000 MB hard drive; comes in either a twodrive or five-drive configuration

Note: Refer to Take Apart for more information on the twodrive configuration and to Additional Procedures for more information on the five-drive configuration.

	Specifications	Disk Storage - 5
DDS-DC Drive		2 GB digital data storage-data compression drive for 4 mm tape
		backup; available as an upgrade on the Quadra 900 and 950;
		optional on the AWS 95

Specifications	I/O Interfaces - 6

SCSI

Quadra 900

AWS 95 and Quadra 900/950 (with PDS card upgrade)

Apple Desktop Bus

I/O Interfaces

One external SCSI port; DB-25 connector

One internal SCSI port with 50-pin IDC connector; Supports a maximum of eight devices (including the computer, which is always device 7)

Two internal SCSI ports with 50-pin IDC connectors; Two external SCSI ports with DB-25 connectors; Supports a theoretical limit of 20 devices (including the computer, which is always device 7) on four separate SCSI buses (two internal and two external); Macintosh Operating System supports only 7 devices

One Apple Desktop Bus (ADB) port; low-speed, synchronous serial interface

	Specifications	I/O Interfaces - 7
NuBus		Five slots support standard and oversize cards, burst-mode
		transfers, a processor write buffer, and NuBus '90; 96-pin
		Euro-DIN connectors
Expansion		One 68040 processor-direct slot (PDS) with 140-pin connector
Serial		Two RS-232/RS-422 ports with mini DIN-8 connectors;
		230.4 Kbits/sec. maximum; 0.920 Mbits/sec. if external clock
		source is provided (modem interface only)
		Asynchronous, synchronous (modem only), and AppleTalk
		(printer only) protocols supported
Sound		8-bit stereo output; 8-bit monoaural input
		Supports electret-type microphone

	Specifications	I/O Interfaces - 8
Video		Supports Apple monitors (8-bit), VGA monitors, and NTSC and
		PAL video standards
Ethernet		One Ethernet port, AUI-15 connector

Specifications	Sound and Video - 9

Sound and Video

Video Display

Built-in 8-bit video circuitry (upgradeable to 24-bit) Supports Apple 8-bit monitors and many non-Apple monitor

types (NTSC, PAL, VGA)

Sound Generator

Microphone

Four-voice, wavetable synthesis

Stereo sampling generator

Electret, omnidirectional; output voltage is 4 mV, peak to peak, at normal value

Specifications	Electrical - 10

Electrical

Line Voltage

Line Frequency

Maximum Power

100–240 VAC (RMS), self-configuring power supply

50–60 Hz, single phase

303 W (not including monitor)

	Specifications	Physical - 11
		Physical
Dimensions		Height: 16.8 in. (473 mm)
		Width: 8.9 in. (224 mm)
		Depth: 20.6 in. (523 mm)
Weight		36 lb., 12 oz. (16.7 kg) without hard drive

Specifications	Environmental - 12

Environmental

Operating Temp

Storage Temp

Relative Humidity

Altitude

50–104° F (10–40° C)

–40 to 116.6° F (–40 to 47° C)

20–80% noncondensing

0–10,000 ft. (0–3048 m)

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Troubleshooting

Macintosh Quadra 900/950/AWS

95

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	General - 2

Error Chords

One-part error chord sounds during startup sequence

Two-part error chord sounds during startup sequence

1Disconnect SCSI data cable from logic board and reboot system. If startup sequence is normal, initialize hard drive. If error chord still sounds, replace hard drive.

2Disconnect floppy drive cable connector and reboot system. If startup sequence is normal, replace floppy drive.

3Replace logic board. Retain customer's SIMMs.

Perform SIMM verification. Refer to Memory manual.

Troubleshooting General - 3

System Problems

Does not power on;	1	Check power cables.
screen is black, fan is	2	Plug monitor directly into wall socket and verify that
not running, and LED		monitor has power.
is not lit	3	Replace power cord.
	4	Replace power supply.
	5	Replace logic board. Retain customer's SIMMs.
Clicking, chirping,	1	Replace power supply.
or thumping	2	Replace logic board. Retain customer's SIMMs.
	3	Replace floppy drive cable.
	4	Replace floppy drive.

Troubleshooting General - 4

System Problems (Continued)

System shuts down	1	Make sure air vents on side and rear of computer are clear.
intermittently		Thermal protection circuitry may shut down system. After
		30 to 40 minutes, system should be OK.
	2	Replace power cord.
	3	Check battery. Refer to "Battery Verification" in Additional
		Procedures.
	4	Replace power supply.
	5	Replace logic board. Retain customer's SIMMs.

Troubleshooting General - 5

System Problems (Continued)

System	1	Verify that system software is correct version.
intermittently	2	Verify that software is known-good.
crashes or hangs	3	Verify that software is System 7 compatible.
	4	Clear parameter RAM. Hold down <Command> <Option> <P>
		<R> during startup but before "Welcome To Macintosh"
		appears.
	5	Replace SIMMs. Refer to Memory manual.
	6	Replace logic board. Retain customer's SIMMs.
	7	Replace power supply.

Troubleshooting General - 6

Video

Screen is black, audio	1	Adjust brightness on monitor.
and drive operate, fan	2	Replace monitor. Refer to appropriate monitor manual to
is running, and LED is		troubleshoot defective monitor.
lit	3	Replace video cable.
	4	If a video interface card is installed, move it to a different
		slot.
	5	Replace video interface card, if installed.
	6	Clear parameter RAM. Hold down <Command> <Option> <P>
		<R> during startup but before "Welcome To Macintosh"
		appears.
	7	Replace SIMMs. Refer to Memory manual.
	8	Replace logic board. Retain customer's SIMMs.
	9	Replace power supply.

	Troubleshooting		General - 7
		Video (Continued)
Screen is black, audio		1	Replace video cable.
and drive do not		2	If a video interface card is installed move it to a different
operate, but fan is			slot.
running and LED is lit		3	Replace video interface card, if installed.
		4	Replace SIMMs. Refer to Memory manual.
		5	Replace logic board. Retain customer's SIMMs.
		6	Replace power supply.

	Troubleshooting		General - 8
		Video (Continued)
Partial or whole		1	Replace monitor. Refer to appropriate monitor manual to
screen is bright and			troubleshoot defective monitor.
audio is present, but		2	Replace video cable.
no video information		3	If a video interface card is installed, move it to a different
is visible			slot.
		4	Replace video interface card, if installed.
		5	Clear parameter RAM. Hold down <Command> <Option> <P>
			<R> during startup but before "Welcome To Macintosh"
			appears.
		6	Replace logic board. Retain customer's SIMMs.

Troubleshooting General - 9

Floppy Drive

Internal floppy drive	1	Verify that keyswitch is not set to secure.
does not operate	2	Replace disk with known-good disk.
	3	Replace floppy drive cable.
	4	Replace internal floppy drive.
	5	Replace logic board. Retain customer's SIMMs.
	6	Replace power supply.
During system	1	Replace disk with known-good system disk.
startup, disk ejects;	2	Clear parameter RAM. Hold down <Command> <Option> <P>
display shows icon		<R> during startup but before "Welcome To Macintosh"
with blinking "X"		appears.
	3	Replace floppy drive cable.
	4	Replace internal floppy drive.
	5	Replace logic board. Retain customer's SIMMs.

Troubleshooting General - 10

Floppy Drive (Continued)

Does not eject disk	1	Verify that keyswitch is not set to secure.
	2	Switch off computer. Hold mouse button down while you
		switch computer on.
	3	Replace internal floppy drive.
	4	Replace floppy drive cable.
	5	Replace logic board. Retain customer's SIMMs.
Attempts to eject	1	Push disk completely in.
disk, but doesn't	2	Reseat floppy drive bezel and drive so bezel slot aligns
		correctly with drive.
	3	Eject disk manually.
	4	Replace floppy drive.

Troubleshooting	General - 11

Floppy Drive (Continued)

Internal floppy drive runs continuously

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

1Replace disk with known-good system disk.

2Replace floppy drive cable.

3Replace internal floppy drive.

4Replace logic board. Retain customer's SIMMs.

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

Troubleshooting General - 12

Hard Drive

Single internal hard	1	Replace hard drive data cable.
drive will not	2	Replace hard drive power cable.
operate; drive doesn't	3	Replace hard drive.
spin
No internal hard	1	Verify there are no duplicate SCSI device addresses.
drives operate	2	Replace hard drive data cable.
	3	Replace power supply.
	4	Replace logic board. Retain customer's SIMMs.

	Troubleshooting		General - 13
		Hard Drive (Continued)
Drive does not appear		1	Verify there are no duplicate SCSI device addresses.
on the desktop		2	Update the SCSI device driver using Apple HD SC 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 HD SC Setup to initialize.
		5	Replace with known good hard drive. If the hard drive still
			doesn't work, switch back to the original hard drive and
			replace the logic board.
Works with internal		1	Verify there are no duplicate SCSI device addresses.
or external SCSI		2	Replace terminator on external device.
devices but not with		3	Make sure internal hard drives are not terminated.
both		4	Refer to appropriate manual to troubleshoot defective
			external device.