Macintosh Classic, Classic II, Performa 200 Service Source

K

Service Source

Macintosh Classic/

Classic II/Performa 200

K

Service Source

Basics

Macintosh Classic/Classic II/

Performa 200

Basics Overview - 1

Overview

This manual includes
complete repair procedures
for the Macintosh Classic,
Classic II, and Performa

200.

Figure: Macintosh Classic/Classic II and Performa 200

K

Service Source

Specifications

Macintosh Classic/Classic II/

Performa 200

Specifications Processor - 1

Processor

Classic CPU

Classic II/Per 200
CPU

Motorola 68000 microprocessor

7.8336 MHz
32-bit internal data bus
256-byte instruction and data caches

Motorola 68030 microprocessor
16 MHz
32-bit internal data bus
256-byte instruction and data caches

RAM

Specifications Memory - 2

Memory

Classic:
Classic II/Per 200:

ROM

PRAM

Cache Connector

1 MB, expandable to 4 MB (120 ns or faster SIMMs)
2 MB, expandable to 10 MB (120 ns or faster SIMMs)

512K

256 bytes of parameter memory

44-pin connector for optional memory expansion
256K by 4-bit DRAMs
Includes two SIMM connectors for additional RAM expansion

Specifications Disk Storage - 3

Disk Storage

Floppy Drive

Hard Drive

Classic:
Classic II/Per 200:

Internal 1.4 MB floppy drive
Optional external 800K or 1.4 MB floppy drive

Optional internal 40 MB hard drive; optional external SCSI drive
Internal 40 MB or 80 MB hard drive; optional external SCSI

drive

Specifications I/O Interfaces - 4

I/O Interfaces

Floppy Drive

SCSI

Apple Desktop Bus

Serial

Sound

External drive port; DB-19 connector

One SCSI parallel port; DB-25 connector

One Apple Desktop Bus (ADB) port; mini DIN-4 connector

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

Dual-channel headphone connector
Connected to the monophonic sound output
Macintosh Classic does not provide true two-channel output

(although stereo jack may be used)

Specifications I/O Devices - 5

I/O Devices

Keyboard

Mouse

Classic II/Per 200
Microphone

80 keys, with numeric keypad; ADB connector

Mechanical tracking; ADB connector

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

normal volume

Specifications Sound and Video - 6

Sound Generator

Sound and Video

Classic:

Video Display

Classic II/Per 200:

Four-voice sound with 8-bit digital/analog conversion, using

22-kHz sampling rate

Monophonic, 8-bit digital/analog conversion using 22-kHz

sampling rate; capable of driving stereo headphones or other
stereo equipment through the sound jack

9-in. (diagonal) screen; high-resolution, 512 by 342 pixel,

bit-mapped, monochrome display

Specifications Electrical - 7

Electrical

Line Voltage

Frequency

Maximum Power

100–120 V AC

47–63 Hz, single phase

100 W

Specifications Physical - 8

Physical

Dimensions

Weight

Height: 13.2 in. (33.6 cm)
Width: 9.7 in. (24.6 cm)
Depth: 11.2 in. (28.5 cm)

16–17.1 lb. (7.3-7.8 kg) not including internal hard drive

Service Source

K

Troubleshooting

Macintosh Classic/Classic II/

Performa 200

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/Video - 2

Symptom Charts

Video

Screen is dark; audio
and drive operate

1 Readjust brightness (see Adjustments).
2 Readjust contrast (see Adjustments).
3 Check yoke cable connection.
4 Replace power/sweep board.
5 Replace logic board. Retain customer’s SIMMs.
6 Replace CRT.

Screen is bright and
audio is present, but
no video information
is visible

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

Troubleshooting Symptom Charts/Video

(Continued)

- 3

Video

(Continued)

Screen is dark; fan is
not running

Replace power/sweep board.

Single vertical line is
displayed

1 Replace power/sweep board.
2 Replace logic board. Retain customer’s SIMMs.
3 Replace CRT.

Single horizontal line
is displayed

1 Replace power/sweep board.
2 Replace logic board. Retain customer’s SIMMs.
3 Replace CRT.

Vertical bars or
stripes are displayed

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

Troubleshooting Symptom Charts/Video

(Continued)

- 4

Video

(Continued)

Horizontal bars or
stripes are displayed

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

White dot is displayed
in center of screen

1 Verify that yoke cable is connected.
2 Replace power/sweep board.
3 Replace CRT.

Screen jitters 1 Move computer away from adjacent monitors or other

electrical equipment that may cause interference.

2 Replace power/sweep board.

Troubleshooting Symptom Charts/Video

(Continued)

- 5

Video

(Continued)

After replacement of
failed hard drive,
video distortion
appears in upper and
lower corners of
screen

Check whether hard drive replacement was like-for-like. If not,
install a like drive.

Troubleshooting Symptom Charts/Floppy Drives - 6

Floppy Drives

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

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

External floppy drive
does not operate

1 Replace bad disk with known-good disk.
2 Be sure external floppy drive is placed on right side of

computer.
3 Replace external floppy drive.
4 Replace logic board. Retain customer’s SIMMs.

Disk ejects; display
shows icon with
blinking “X”

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

Troubleshooting Symptom Charts/Floppy Drives

(Continued)

- 7

Floppy Drives

(Continued)

Unable to insert disk
all the way

1 Insert opened paper clip into hole beside floppy drive.
2 Switch off system and hold mouse button down while

switching system on (to complete eject cycle).
3 Replace floppy drive.

Does not eject disk 1 Insert opened paper clip into hole beside floppy drive.

2 Switch off system and hold mouse button down while

switching system on (to complete eject cycle).
3 Replace floppy drive.

Internal floppy drive
runs continuously

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

Troubleshooting Symptom Charts/Hard Drives - 8

Hard Drives

Internal or external
hard drive does not
operate

1 Verify that SCSI loopback card is not attached.
2 Check that internal SCSI terminator is positioned in

connector properly.
3 Verify that internal hard drive has all three terminating

resistor packs on circuit board.
4 Replace hard drive data cable.
5 Replace hard drive.
6 Replace logic board. Retain customer’s SIMMs.

Works with internal
or external SCSI
device but does not
work with both.

1 Verify that SCSI device ID switch setting on external device

is higher than 0. Also verify that ID switch setting on

external SCSI device does not duplicate ID switch settings on

any other attached external SCSI devices.
2 Replace terminator on external SCSI device.
3 Verify that terminator is installed on internal SCSI drive.
4 Replace SCSI select cable.

Troubleshooting Symptom Charts/Peripheral - 9

Peripheral

Cursor does not move 1 Check mouse connection.

2 If mouse was connected to keyboard, connect it to rear ADB

port instead. If mouse works, replace keyboard.
3 If mouse does not work in any ADB port, replace mouse.
4 Replace logic board. Retain customer’s SIMMs.

Cursor moves, but
clicking the mouse
button has no effect

1 Replace mouse.
2 Replace logic board. Retain customer’s SIMMs.

Troubleshooting Symptom Charts/Peripheral

(Continued)

- 10

Peripheral

(Continued)

Cannot double-click
to open application,
disk, or server

1 Remove extra system files on hard drive.
2 Clear parameter RAM. Hold down <Shift> <Option>

<Command> keys and select Control Panel from Apple pull-

down menu. Reset mouse controls.
3 If mouse was connected to keyboard, connect it to rear ADB

port instead. If mouse works, replace keyboard.
4 If mouse does not work in any ADB port, replace mouse.
5 Replace logic board. Retain customer’s SIMMs.

No response to any
key on keyboard

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

Troubleshooting Symptom Charts/Peripheral

(Continued)

- 11

Peripheral

(Continued)

Known-good
ImageWriter or
ImageWriter II does
not print

1 Make sure that Chooser and Control Panel are set correctly.
2 Replace printer driver and system software with known-

good.
3 Replace printer interface cable.
4 Replace logic board. Retain customer’s SIMMs.

Known-good
LaserWriter does not
print.

1 Make sure that Chooser and Control Panel are set correctly.
2 Replace printer driver and system software with known-

good.
3 Refer to Networks manual.

Troubleshooting Symptom Charts/Miscellaneous - 12

Miscellaneous

Clicking, chirping,
or thumping sound

1 Verify that logic board power cable is connected at J12 on

logic board.
2 Replace power/sweep board.
3 Replace logic board. Retain customer’s SIMMs.

Smoke/odor Replace power/sweep board.

No video, no audio, and
no drive operation

1 Connect power cord.
2 Switch power on.
3 Replace power cord.
4 Replace fuse.
5 Replace power/sweep board.
6 Replace logic board. Retain customer’s SIMMs.

Troubleshooting Symptom Charts/Miscellaneous

(Continued)

- 13

Miscellaneous

(Continued)

“Sad Macintosh” icon 1 Replace bad disk with known-good disk.

2 Verify that jumper on memory expansion board is configured

correctly for “SIMMs” or “No SIMMs.” (See “Memory

Upgrade” in Additional Procedures.)
3 On 4 MB Macintosh Classic, confirm SIMMs used are eight-

chip SIMMs. (See Memory manual.) Any 1 MB SIMMs with

fewer than eight chips won’t work in the Macintosh Classic.
4 On Macintosh Classic, replace optional memory expansion

board; on Macintosh Classic II/Performa 200, replace

optional SIMMs in two SIMMs slots on logic board.
5 Replace logic board. Retain customer’s SIMMs.

Troubleshooting Symptom Charts/Miscellaneous

(Continued)

- 14

Miscellaneous

(Continued)

Screen shows “Sad
Macintosh” icon and
black vertical lines;
screeching sound

1 Verify that jumper on memory expansion board is configured

correctly for “SIMMs” or “No SIMMs.” (See “Memory

Upgrade” in Upgrades.)
2 On 4 MB Macintosh Classic, confirm SIMMs used are eight-

chip SIMMs. (See Memory manual.) Any 1 MB SIMMs with

fewer than eight chips won’t work in the Macintosh Classic.
3 On Macintosh Classic, replace optional memory expansion

board; on Macintosh Classic II/Performa 200, replace

optional SIMMs in two SIMMs slots on logic board.
4 Replace logic board. Retain customer’s SIMMs.

Troubleshooting Symptom Charts/Miscellaneous

(Continued)

- 15

Miscellaneous

(Continued)

No power 1 Connect power cord.

2 Switch power on.
3 Replace power cord.
4 Replace fuse.
5 Replace power/sweep board.
6 Replace logic board. Retain customer’s SIMMs.

K

Service Source

Take Apart

Macintosh Classic/Classic II/

Performa 200

Take Apart Cover - 1

Cover

No preliminary steps are
required before you begin
this procedure.

±

Warning:

contains high voltage and a
high-vacuum picture tube.
To prevent serious personal
injury or equipment
damage, review CRT safety
and discharge instructions
in Bulletins/Safety.

This product

Take Apart Cover - 2

1 Using a Torx

screwdriver, remove
the four case screws.
Using a case spreader or
pull-apart tool,
separate the cover from
the chassis.

2 Carefully lift the cover

and set it aside.

±

Warning:

the metal chassis may be
sharp. When moving the
computer with the cover off,

The edges of

be sure to handle the chassis
carefully.

Take Apart Cover - 3

Note:

When replacing the
cover, be sure to install the
two black case screws in the
bottom of the cover and the
two silver-colored case
screws in the top of the
cover.

Take Apart Power/Sweep Board - 4

Power/Sweep
Board

Before you begin:

• Remove the cover

• Discharge the CRT

• Remove the anode cap

±

Warning:

contains high voltage and a
high-vacuum picture tube.
To prevent serious personal
injury or equipment
damage, review CRT safety

This product

and discharge instructions
in Bulletins/Safety.

Caution:

To prevent ESD

Take Apart Power/Sweep Board - 5

damage to components, wear
a grounding wriststrap.
Never use a grounding
wriststrap until after
discharging the CRT.

Take Apart Power/Sweep Board - 6

1 Using a Torx

screwdriver, remove
the screw that secures
the ground wire to the
upper corner of the CRT.

2 Carefully pull off the

video board from the
neck of the CRT.

Note:

If sealant holds
the board in place, cut
the sealant with an art
knife.

Take Apart Power/Sweep Board - 7

3 Remove the logic board

power cable from the
logic board. Remove the
Phillips screws that
secure the power/sweep
bracket to the chassis
and pull the board
slightly away from the
chassis.

Note:

Most power/sweep
brackets are secured by
two screws; however,
some are secured by
three.

Take Apart Power/Sweep Board - 8

5 Remove the following

cable connectors from
the power/sweep board:

• Yoke cable

• Fan cable

• Hard drive power

cable (if present)

Take Apart Power/Sweep Board - 9

6 Lift the board free.

Take Apart Power/Sweep Board - 10

Note:

The two versions of
the power/sweep board,
Rev A and Rev B, are
functionally equivalent, but
they are not
interchangeable.

In addition, a Rev A power/
sweep board must be used
with a Rev A CRT yoke
assembly and a Rev A or Rev
B cover. A Rev B power/
sweep board must be used
with a Rev B CRT yoke
assembly and a Rev B cover.

Take Apart Power/Sweep Board - 11

To identify compatible
versions of the power/sweep
board, CRT assembly, and
cover, examine the CRT yoke
connector. Power/sweep
board Rev A has plastic
sleeves surrounding the
prongs; the prongs are
exposed on power/sweep
board Rev B.

Take Apart Logic Board - 12

Logic Board

Before you begin:

• Remove the cover

• Discharge the CRT

• Remove the memory

expansion board

±

Warning:

contains high voltage and a
high-vacuum picture tube.
To prevent serious personal
injury or equipment
damage, review CRT safety

This product

and discharge instructions
in Bulletins/Safety.

Take Apart Logic Board - 13

Caution:

To prevent ESD
damage to components, wear
a grounding wriststrap.
Never use a grounding
wriststrap until after
discharging the CRT.

Take Apart Logic Board - 14

1 Remove the following

cable connectors from
the logic board:

• Logic board power
cable

• Floppy drive cable

• Hard drive data
cable (if present)

Hard Drive

Data Cable

Floppy Drive Cable

Take Apart Logic Board - 15

2 Grasp the logic board by

the corners and slide it
straight up and out of the
chassis.

Replacement Note:

Remove
the SIMMs from the
defective logic board and
install them in the
replacement logic board.
(See Memory manual.)

Take Apart Hard Drive - 16

Hard Drive

Before you begin:

• Remove the cover

• Discharge the CRT

±

Warning:

contains high voltage and a
high-vacuum picture tube.
To prevent serious personal
injury or equipment
damage, review CRT safety

This product

and discharge instructions
in Bulletins/Safety.

Take Apart Hard Drive - 17

Caution:

To prevent ESD
damage to components, wear
a grounding wriststrap.
Never use a grounding
wriststrap until after
discharging the CRT.

Take Apart Hard Drive - 18

1 Disconnect the hard

drive data cable from the
logic board.

2 Disconnect the hard

drive power cable from
the power/sweep board.

Hard Drive
Power Cable

Hard Drive
Data Cable

Logic Board

Take Apart Hard Drive - 19

3 Remove the two Phillips

screws that secure the
hard drive housing to the
floppy drive housing and
lift out the hard drive
assembly.

Replacement Note:

If you
are removing a hard drive
from the system but not
installing a new one, install
a SCSI terminator on the
logic board SCSI connector.
To insert the terminator,
line up the white key icon
with the notch in the cable
connector.

Take Apart Hard Drive - 20

Replacement Note:

For
information on removing the
hard drive from the carrier
and returning drives,
cables, and carriers to
Apple, refer to Hardware/
Service Manuals/ SCSI Hard
Drives Manual.

Take Apart Floppy Drive - 21

Floppy Drive

Before you begin:

• Remove the cover

• Discharge the CRT

• Remove the hard drive

• Remove the logic board

±

Warning:

contains high voltage and a
high-vacuum picture tube.
To prevent serious personal
injury or equipment
damage, review CRT safety

This product

and discharge instructions
in Bulletins/Safety.

Caution:

To prevent ESD

Take Apart Floppy Drive - 22

damage to components, wear
a grounding wriststrap.
Never use a grounding
wriststrap until after
discharging the CRT.

Take Apart Floppy Drive - 23

1 Remove the four Phillips

screws that secure the
floppy drive housing to
the bottom of the chassis.

Take Apart Floppy Drive - 24

2 Lift out the floppy drive

mechanism.

Replacement Note:

Before
you install a replacement

1.4 MB SuperDrive, you
must remove the dust shield.

Take Apart Fan - 25

Fan

Before you begin:

• Remove the cover

• Discharge the CRT

• Remove the anode cap

• Remove the power/sweep

board

±

Warning:

contains high voltage and a

This product

Fan

high-vacuum picture tube.
To prevent serious personal
injury or equipment
damage, review CRT safety
and discharge instructions
in Bulletins/Safety.

Take Apart Fan - 26

Caution:

To prevent ESD
damage to components, wear
a grounding wriststrap.
Never use a grounding
wriststrap until after
discharging the CRT.

Take Apart Fan - 27

1 Using a small, stump-

handled Phillips
screwdriver, remove
the two screws that
mount the fan to the
chassis.

2 Lift out the fan.

Take Apart CRT - 28

CRT

Before you begin:

• Remove the cover

• Discharge the CRT

• Remove the anode cap

• Remove the power/sweep

board

±

Warning:

contains high voltage and a
high-vacuum picture tube.
To prevent serious personal
injury or equipment

This product

damage, review CRT safety
and discharge instructions
in Bulletins/Safety.

Take Apart CRT - 29

Caution:

To prevent ESD
damage to components, wear
a grounding wriststrap.
Never use a grounding
wriststrap until after
discharging the CRT.

Take Apart CRT - 30

1 Remove the three Torx

screws from the
corners of the CRT.

2 Carefully lift the CRT

free from the bezel.

Note:

The CRT yoke
assembly must be
compatible with the power/
sweep assembly, which is
available in two versions,
Rev A and Rev B. CRT yoke
assembly Rev A requires
power/sweep board Rev A.
CRT yoke assembly Rev B
requires power/sweep
board Rev B.

Take Apart CRT - 31

Refer to “Power/Sweep
Board” in Take Apart to
identify CRT and power/
sweep revisions and to
verify compatibility.

Take Apart Chassis & Front Bezel - 32

Chassis & Front
Bezel

Before you begin:

• Remove the cover

• Discharge the CRT

• Remove the anode cap

• Remove the power/sweep

board

• Remove the memory

expansion board

• Remove the logic board

• Remove the hard drive

• Remove the floppy drive

• Remove the fan

Take Apart Chassis & Front Bezel - 33

±

Warning:

contains high voltage and a
high-vacuum picture tube.
To prevent serious personal
injury or equipment
damage, review CRT safety
and discharge instructions
in Bulletins/Safety.

This product

Take Apart Chassis & Front Bezel - 34

1 Remove the four Torx

screws from the front
bezel.

2 Lift out the metal

chassis.

Take Apart Chassis & Front Bezel - 35

3 Remove the three Torx

screws from the corner
of the CRT, and remove
the CRT.

Take Apart Fuse - 36

Fuse

Before you begin:

• Remove the cover

• Discharge the CRT

±

Warning:

contains high voltage and a
high-vacuum picture tube.
To prevent serious personal
injury or equipment
damage, review CRT safety
and discharge instructions
in Bulletins/Safety.

This product

Take Apart Fuse - 37

Caution:

To prevent ESD
damage to components, wear
a grounding wriststrap.
Never use a grounding
wriststrap until after
discharging the CRT.

Using a fuse puller or small
flat-blade screwdriver,
carefully remove the fuse
from its holder.

K

Service Source

Upgrades

Macintosh Classic/Classic II/

Performa 200

Upgrades Memory Exp. Bd. - 1

Memory Exp. Bd.

Before you begin:

• Remove the cover

• Discharge the CRT

±

Memory Expansion

Board

Warning:

contains high voltage and a
high-vacuum picture tube.
To prevent serious personal
injury or equipment
damage, review CRT safety
and discharge instructions
in Bulletins/Safety.

This product

Upgrades Memory Exp. Bd. - 2

Caution:

To prevent ESD
damage to components, wear
a grounding wriststrap.
Never use a grounding
wriststrap until after
discharging the CRT.

Upgrades Memory Exp. Bd. - 3

Note:

The memory
expansion board is an option
for the Macintosh Classic
only. It contains 1 MB of
soldered RAM plus one pair
of SIMM connectors.

Carefully slide the memory
expansion board up to free it
from the logic board and the
chassis.

Upgrades Memory Upgrade - 4

Memory Upgrade

Before you begin:

• Remove the cover

• Discharge the CRT

• Remove the memory

expansion board

±

Memory Expansion

Board

Warning:

contains high voltage and a
high-vacuum picture tube.
To prevent serious personal
injury or equipment
damage, review CRT safety
and discharge instructions

This product

in Bulletins/Safety.

Upgrades Memory Upgrade - 5

Caution:

To prevent ESD
damage to components, wear
a grounding wriststrap.
Never use a grounding
wriststrap until after
discharging the CRT.

Upgrades Memory Upgrade - 6

SIMM Connectors

1 MB soldered RAM

Jumper

Note:

The memory
expansion board is an option
for the Macintosh Classic
only. It contains 1 MB of
soldered RAM plus one pair
of SIMM connectors. You can
upgrade the system further
by adding two 256K or two 1
MB SIMMs to the memory
expansion board and moving
the jumper. You must use
120-ns (or faster) SIMMs.

Upgrades Memory Upgrade - 7

SIMM Connectors

1 MB soldered RAM

Jumper

Note:

Install the memory
board without additional
SIMMs for a 1 MB RAM
upgrade. Install two 256K
SIMMs onto the memory
expansion board for a 2.5
MB RAM upgrade or two 1
MB SIMMs for a 4 MB RAM
upgrade.

1 Install the SIMMs in the

SIMM slots on the
memory expansion
board.

2 Position the jumper as

shown.

Upgrades Classic II Upgrade - 8

Classic II Upgrade

Before you begin:

• Remove the cover

• Discharge the CRT

• Remove the logic board

±

Warning:

contains high voltage and a
high-vacuum picture tube.
To prevent serious personal
injury or equipment
damage, review CRT safety
and discharge instructions

This product

in Bulletins/Safety.

Caution:

damage to components, wear

To prevent ESD

Upgrades Classic II Upgrade - 9

a grounding wriststrap.
Never use a grounding
wriststrap until after
discharging the CRT.

Upgrades Classic II Upgrade - 10

Note:

A Macintosh Classic II
upgrade kit upgrades a
Macintosh Classic to a
Macintosh Classic II. The
upgrade kit includes a
Classic II logic board, a
Classic II cover, a
microphone, and an
accessory kit.

Upgrades Classic II Upgrade - 11

Caution:

Take care that the
connections to the sound
output and sound input
ports are correct. Inserting
the wrong equipment into
the wrong port could damage
the Macintosh Classic II or
external equipment.

1 Install the Macintosh

Classic II logic board.

Upgrades Classic II Upgrade - 12

Serial Number

2 Install the Classic II

cover.

3 Read the customer’s

original serial number
from the label on the
back of the old rear
housing and record the
number with indelible
ink or engrave it onto
the new rear housing.

K

Service Source

Additional Procedures

Macintosh Classic/Classic II/

Performa 200

Additional Procedures Battery Verification - 1

Battery
Verification

Before you begin:

• Remove the cover

• Discharge the CRT

• Remove the logic board

±

Warning:

contains high voltage and a
high-vacuum picture tube.
To prevent serious personal
injury or equipment
damage, review CRT safety

This product

and discharge instructions
in Bulletins/Safety.

Caution:

To prevent ESD

Additional Procedures Battery Verification - 2

damage to components, wear
a grounding wriststrap.
Never use a grounding
wriststrap until after
discharging the CRT.

Additional Procedures Battery Verification - 3

±

Warning:

discarded improperly, the
lithium battery in the
computer could explode.
Review battery handling and
disposal instructions in
Bulletins/Safety.

1 Set the voltmeter range

to the10 volts DC scale.

2 Hold the positive probe

of the voltmeter to the
positive “+” side of the
battery. Hold the ground

If handled or

probe of the voltmeter to
the negative (-) side of
the battery.

Additional Procedures Battery Verification - 4

3 If the battery voltage is

below 3.0 volts, replace
the battery. See
“Battery Replacement”
in this chapter.

Additional Procedures Battery Replacement - 5

Battery
Replacement

Before you begin:

• Remove the cover

• Discharge the CRT

• Remove the logic board

±

Warning:

contains high voltage and a
high-vacuum picture tube.
To prevent serious personal
injury or equipment
damage, review CRT safety

This product

and discharge instructions
in Bulletins/Safety.

Additional Procedures Battery Replacement - 6

Caution:

To prevent ESD
damage to components, wear
a grounding wriststrap.
Never use a grounding
wriststrap until after
discharging the CRT.

Additional Procedures Battery Replacement - 7

±

Warning:

discarded improperly, the
lithium battery in the
computer could explode.
Review battery handling and
disposal instructions in
Bulletins/Safety.

1 Pull the old battery out

of the battery holder.

2 Replacement Note:

Orient the new battery
so that the end marked
“+” matches the “+” on

If handled or

the logic board, and
insert the battery into
the battery holder.

Additional Procedures Battery Replacement - 8

Note:

For information about
properly disposing of the old
battery, refer to battery
disposal instructions in
Bulletins/Safety.

K

Service Source

Adjustments

Macintosh Classic/Classic II/

Performa 200

Adjustments Light Meter Setup - 1

Light Meter Setup

Side

Switch

Read Button

Note:

setup for two light meters:
Models L-248 and 246.

This topic covers

Model L-248

1 Press the red button on

the back of the light
meter. If the reading is
out of the red bar,
replace the battery.

2 Luminance tests will

instruct you to move the
side switch either to the
low position (2-10) or

Adjustments Light Meter Setup - 2

the high position (10-

18) to get a reading.

3 Uncover the lens of the

Side

Switch

Read Button

meter.

4 Place the lens against the

middle of the screen and
press the Read button.

Adjustments Light Meter Setup - 3

Model 246

Lens

Red Scale

Note:

Remove the metal
slide, if installed, from the
top of the light meter.
Install the white lens with
the red dot.

1 Rotate the lens for the

meter so the lens faces
the monitor and the scale
faces you.

2 Use your hand to shield

the lens from ambient
light.

3 Place the lens against the

middle of an all-white
screen.

Adjustments Light Meter Setup - 4

4 Read the red scale while

you perform the
Brightness and Contrast
adjustments in the Video
topic.

Adjustments Video - 5

Video

Note:

CRT or power/sweep board,
you may need to perform
video adjustments.

1

After you replace the

Caution:

must make adjustments
from the rear of the
computer, position a
mirror to view the
computer screen.

Because you

Adjustments Video - 6

2 Using a small flat-blade

screwdriver, depress
the center tab and lift
out the service door.

Adjustments Video - 7

Brightness & Contrast

Contrast
(PL2)

Brightness

(PL4)

Important:

Readings from
light meters may differ
between models. Please note
the type of meter you are
using (Model L-248 or

246) before making an
adjustment. (See “Light
Meter Setup.”)

Note:

Be sure the computer
has been on for at least 30
minutes.

1 Run the Display Service

Utility from the Utilities
folder on the MacTest
Pro CD.

Adjustments Video - 8

2 From the pattern

selections screen, select
the Full brightness
screen.

3 Hold the light meter

lens against the center of
the screen.

4 Using an insulated flat-

blade screwdriver,
adjust the contrast
control until you
measure luminance at
40 foot lamberts (± 3

foot lamberts), which on
the light meter is

• Model L-248: 10 to
11 on the 10-18 scale

Adjustments Video - 9

• Model 246: 29 on the
red scale

Important:

Over time,
light meter tolerance can
vary. If you doubt your
meter’s accuracy,
verify the readings with
a known-good light
meter or photometer.

5 Press a key to return to

the pattern selections
screen. Select the Half
brightness screen.

Adjustments Video - 10

6 Using a plastic hex

alignment tool, adjust
the brightness control
until the luminance at
the center of the screen
measures 5 foot
lamberts (± 1 foot
lambert), which on the
light meter is

• Model L-248: high

end of 7 on the 2-10
scale

Brightness

(PL4)

• Model 246: 5 on the

red scale

Adjustments Video - 11

7 Press a key to return to

the pattern selections
screen. Select the Full
brightness screen.

8 Recheck the luminance at

the center of the screen:

• Model L-248: 10 to

11 on the 10-18 scale

• Model: 246: 29 on the

red scale

If the light meter
reading does not match
the luminance

meaurement shown,
repeat the brightness &
contrast procedure.