Apple Multiple Scan 720 Display Service Manual

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Service Source

Apple Multiple Scan 720 Display

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Service Source

Hot Issues

Apple Multiple Scan 720 Display

Hot Issues Introduction - 1

Introduction

This chapter is designed to highlight unique or high­priority product issues that you should be aware of before
servicing this display.

This chapter alerts you to important issues and provides
links to other areas in the manual where more complete
information can be found. This chapter is not intended to
replace other parts of this manual; it merely provides a
pointer to pertinent information in those chapters.

Hot Issues Jittery or Blurry Video with Power Macintosh 5500/6500 - 2

Jittery or Blurry Video with Power
Macintosh 5500/6500

If the display exhibits jittery or blurry video when
connected to a Power Macintosh 5500 or 6500, suspect the
computer, not the monitor.

Video jitter affects monitors connected to computers having
a 225 or 250 MHz logic board. Jitter is evident where the
pixels shimmer or jump at the edges of the screen, windows,
or dialog boxes.

Blurry video is seen as a fuzzy image over the entire screen
on monitors set to resolutions of 832x624 and higher.

Hot Issues Jittery or Blurry Video with Power Macintosh 5500/6500 - 3

Identifying Suspect Units

Video jitter or blurry video can be caused by Power
Macintosh computers within the following serial number
ranges.

Video Jitter

• PM 5500 from TY705xxxxx to TY715xxxxx

• PM 6500 from XB708xxxxx to XB718xxxxx

Blurry Video

• PM 6500 from XB708xxxxx to XB723xxxxx

The system software on Power Macintosh 6500 computers
allows selecting monitor resolutions above 1152x870. But
these higher resolutions are not supported and cause poor
video output, such as misaligned or skewed video, low
brightness, blurriness, and so on. Monitors connected to

Hot Issues Jittery or Blurry Video with Power Macintosh 5500/6500 - 4

Power Macintosh 6500 computers should not be set to
resolutions higher than 1152x870.

Check the control strip to make sure the resolution is set to
1152x870 or lower. For a chart of supported monitor
resolutions for the Power Macintosh 6500, see the
Specifications chapter in the Performa/Power Macintosh
6400 and 6500 Series manual on Service Source.

Although these symptoms have never been reported for a
Power Macintosh 5500, the 225 MHz logic board used in the
Power Macintosh 6500 is also used in the 5500. Refer to
the Troubleshooting chapter in Service Source for both
Power Macintosh manuals.

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Basics

Apple Multiple Scan 720 Display

Basics Overview - 1

Overview

The Apple Multiple Scan
720 Display is a low-cost
17-inch (16.0-inch
viewable image size)
monitor. It offers screen
resolutions ranging from
640x480 to 1280x1024.

The Apple Multiple Scan
720 Display complies with
TCO 95 as certified by the
Swedish confederation of
Professional Employees to
meet global safety tests and
energy-saving features.

Basics Overview - 2

Features

Features of the Apple Multiple Scan 720 Display include

• 17-inch (16.0-inch VIS) CRT

• 0.28 mm dot pitch

• Multiple resolutions

• User controls for brightness, contrast, and On-Screen
Display geometry controls

• Mac OS-based and Windows-based compatibility

• Energy Star compliance

• TCO 95 compliance

Basics Overview - 3

The front panel of the
display includes the
following controls:

• Power button

• Brightness

• Contrast

• On-Screen Display
(OSD) select/adjust
control

• On-Screen Display
(OSD) enter button

Refer to the Adjustments
chapter for a list of
picture-quality adjustments
that can be made using the
On-Screen Display.

Basics Overview - 4

Repair and Replacement Tips

The monitor stand does not need to be removed before the
rear housing is removed, however the monitor stand is
easiest to remove when the monitor is completely assembled.

When the rear housing is removed, special care must be
taken to avoid damaging the monitor assembly. The rear
housing helps support the weight of the main deflection
board and CRT/video board.

The CRT/video board and the main deflection board cannot be
separated without risk of damaging the CRT socket.
Therefore, the CRT/video board and main deflection board
are offered as one module.

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Specifications

Apple Multiple Scan 720 Display

Specifications Characteristics - 1

Characteristics

Picture Tube

Screen Resolution

17-in. diagonal flat square CRT (16.0-in. diagonal viewable

image)

Multiple scan, antistatic, antiglare surface treatment

0.28-mm dot pitch

640x480 at 60 Hz in VGA mode
640x480 at 66.7 Hz in Macintosh mode
640x480 at 85 Hz in VESA mode
800x600 at 60 Hz in VESA mode
800x600 at 72 Hz in VESA mode
800x600 at 85 Hz in VESA mode
832x624 at 75 Hz in Macintosh mode
1024x768 at 60 Hz in VESA mode
1024x768 at 70 Hz in VESA mode

Specifications Characteristics - 2

1024x768 at 75 Hz in VESA mode
1024x768 at 85 Hz in VESA mode
1152x870 at 75 Hz in Macintosh mode
1280x1024 at 60 Hz in VESA mode

Scan Rates

Cable Connector

Input Signals

Vertical refresh rate: 48–160 Hz
Horizontal scan rate: 30–70 kHz

15-pin miniature D-type

Red, green, and blue signals; separate sync

Specifications Characteristics - 3

System Requirements

Power Macintosh, Macintosh Performa, and Macintosh Quadra

computers with 68040 or later microprocessors running
Macintosh Operating System software version 7.5 or later

Windows and MS-DOS software-based computers using VGA

(adapter required)

Specifications Characteristics - 4

Monitor Timings

640x480
Resolution @ 60 Hz

Horizontal Timing Horizontal Timing
1/H: 31.5 kHz 1/H: 35 kHz
Back Porch: 48 dots Back Porch: 96 dots
H SYNC: 96 dots negative H SYNC: 64 dots negative
Front Porch: 16 dots Front Porch: 64 dots
1 H: 31.75 µs 1 H: 28.6 µs
1/dot: 25.175 MHz 1/dot: 30.24 MHz

Vertical Timing Vertical Timing
1 V: 16.7 ms 1 V: 15.0 ms
Back Porch: 33 H Back Porch: 39 H
V SYNC: 2 H negative V SYNC: 3 H negative
Front Porch: 10 H Front Porch: 3 H

640x480
Resolution @ 66.7 Hz

Specifications Characteristics - 5

Monitor Timings

640x480
Resolution @ 85 Hz

Horizontal Timing Horizontal Timing
1/H: 43.26 kHz 1/H: 37.87 kHz
Back Porch: 80 dots Back Porch: 88 dots
H SYNC: 56 dots negative H SYNC: 128 dots positive
Front Porch: 56 dots Front Porch: 40 dots
1 H: 23.11 µs 1 H: 26.40 µs
1/dot: 36.000 MHz 1/dot: 40.000 MHz

Vertical Timing Vertical Timing
1 V: 11.8 ms 1 V: 16.6 ms
Back Porch: 25 H Back Porch: 23 H
V SYNC: 3 H negative V SYNC: 4 H positive
Front Porch: 1 H Front Porch: 1 H
1/V: 85 Hz 1/V: 60 Hz

800x600
Resolution @ 60 Hz

Specifications Characteristics - 6

Monitor Timings

800x600
Resolution @ 72 Hz

Horizontal Timing Horizontal Timing
1/H: 48.0 kHz 1/H: 53.67 kHz
Back Porch: 64 dots Back Porch: 152 dots
H SYNC: 120 dots positive H SYNC: 64 dots positive
Front Porch: 56 dots Front Porch: 32 dots
1 H: 20.80 µs 1 H: 18.6 µs
1/dot: 50.000 MHz 1/dot: 56.250 MHz

Vertical Timing Vertical Timing
1 V: 13.9 ms 1 V: 11.8 ms
Back Porch: 23 H Back Porch: 27 H
V SYNC: 6 H positive V SYNC: 3 H positive
Front Porch: 37 H Front Porch: 1 H

800x600
Resolution @ 85 Hz

Specifications Characteristics - 7

Monitor Timings

832x624
Resolution @ 75 Hz

Horizontal Timing Horizontal Timing
1/H: 49.72 kHz 1/H: 48.36 kHz
Back Porch: 224 dots Back Porch: 160 dots
H SYNC: 64 dots negative H SYNC: 136 dots negative
Front Porch: 32 dots Front Porch: 24 dots
1 H: 20.1 µs 1 H: 20.67 µs
1/dot: 57.283 MHz 1/dot: 65.0 MHz

Vertical Timing Vertical Timing
1 V: 13.4 ms 1 V: 16.7 ms
Back Porch: 39 H Back Porch: 29 H
V SYNC: 3 H negative V SYNC: 6 H negative
Front Porch: 1 H Front Porch: 3 H

1024x768
Resolution @ 60 Hz

Specifications Characteristics - 8

Monitor Timings

1024x768
Resolution @ 70 Hz

Horizontal Timing Horizontal Timing
1/H: 56.47 kHz 1/H: 60.023 kHz
Back Porch: 144 dots Back Porch: 176 dots
H SYNC: 136 dots negative H SYNC: 96 dots positive
Front Porch: 24 dots Front Porch: 16 dots
1 H: 17.70 µs 1 H: 16.6 µs
1/dot: 75.000 MHz 1/dot: 78.75 MHz

Vertical Timing Vertical Timing
1 V: 14.3 ms 1 V: 13.3 ms
Back Porch: 29 H Back Porch: 28 H
V SYNC: 6 H negative V SYNC: 3 H positive
Front Porch: 3 H Front Porch: 1 H

1024x768
Resolution @ 75 Hz

Specifications Characteristics - 9

Monitor Timings

1024x768
Resolution @ 85 Hz

Horizontal Timing Horizontal Timing
1/H: 68.677 kHz 1/H: 68.681 kHz
Back Porch: 208 dots Back Porch: 144 dots
H SYNC: 96 dots positive H SYNC: 128 dots negative
Front Porch: 48 dots Front Porch: 32 dots
1 H: 14.561 µs 1 H: 14.56 µs
1/dot: 94.500 MHz 1/dot: 100.00 MHz

Vertical Timing Vertical Timing
1 V: 11.8 ms 1 V: 13.3 ms
Back Porch: 36 H Back Porch: 39 H
V SYNC: 3 H positive V SYNC: 3 H negative
Front Porch: 1 H Front Porch: 3 H

1152x870
Resolution @ 75 Hz

Specifications Characteristics - 10

Monitor Timings

1280x1024
Resolution @ 60 Hz

Horizontal Timing
1/H: 63.8 kHz
Back Porch: 248 dots
H SYNC: 112 dots positive
Front Porch: 48 dots
1 H: 15.6 µs
1/dot: 108 MHz

Vertical Timing
1 V: 16.7 ms
Back Porch: 38 H
V SYNC: 3 H positive
Front Porch: 1 H

Specifications Controls and Ports - 11

Controls and Ports

User Controls

Front panel: power, brightness, contrast, On-Screen Display

Enter, On-Screen Display Select/Adjust

Additional picture controls available when using the On-Screen

Display

Automatic degauss at power-on; manual degauss by selecting

Degauss in the On-Screen Display

Specifications Physical and Electrical - 12

Physical and Electrical

Power Supply

Size and Weight

Voltage: 100–120 VAC; 220–240 VAC
Frequency: 50–60 Hz
Power: 120 W maximum

Height: 17.0 in. (431 mm)
Width: 16.2 in. (412 mm)
Depth: 16.9 in. (428.5 mm)
Weight: 37.5 lb. (17 kg)

Specifications Environmental - 13

Environmental

Temperature

Humidity

Altitude

Operating: 50°F to 104°F (10°C to 40°C)
Shipping: –4°F to +140°F (–40°C to +60°C)
Storage: 32°F to 140°F (0°C to 60°C)

Operating: 20% to 95%, noncondensing

Operating: 0 to 10,000 ft. (0 to 3,048 m)
Transit: 0 to 35,000 ft. (0 to 10,670 m)

Specifications Environmental - 14

Power-Saving and Environmental Features

Conforms to the Energy Star program of the United States

Environmental Protection Agency

Complies with TCO 95 as certified by the Swedish confederation of
Professional Employees to meet global safety tests and energy­saving features

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Troubleshooting

Apple Multiple Scan 720 Display

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.)

For additional assistance, contact Apple Technical Support.

Troubleshooting First Checklist/ - 2

First Checklist

Important:

be fully operational. Read this checklist before you return a
module, and prevent needless module replacement and
unnecessary time delays.

Many display modules returned for repair are found to

The Apple Multiple Scan 720 Display is not
compatible with all computers.

This display works with both Macintosh and IBM PC-compatible
computers. A video card may need to be installed to use this display
with some computers. For more information, see the computer
manual.

The display works with any computer that has the following
timing ranges:

• Horizontal scan rate of 30-70 kHz

• Vertical refresh rate of 48-160 Hz

For best display performance, operate the display in one of the
factory-preset screen resolutions listed in the Specifications
chapter in this manual.

The CRT raster will not always resemble a perfect
rectangle.

CRT tolerances allow for some distortion. Additional distortion can
be caused by magnetized metal objects (desks, file cabinets, etc.).
Move the unit to a different location if you notice raster bowing or
bent raster edges.

Jitter, faint lines, or screen movement can be caused
by external interference such as electronic devices
and fluorescent lights

Fluorescent lights, other monitors, or electronic appliances such
as coffee makers and copy machines can cause raster distortion.
Move the unit to another room or building to help determine if
external interference is the source of the problem.

Note:

If the raster has shifted up/down or right/left only, adjust
it with the user controls. However, keep in mind that if you then
move the monitor you may need to readjust the centering controls.

If the display changes (for better or worse) when you move it to
another location, the environment is the source of the problem.
Relocate the monitor or move the distortion-causing object.

.

Troubleshooting First Checklist/ - 3

A maladjusted screen can mimic the symptoms of
deflection board or CRT failures.

By performing the adjustment procedures, you might determine if
one or more of the adjustments is the cause of the problem.

CRTs rarely fail.

Needless CRT replacement can be prevented by checking display
adjustments, checking the possibility of other defective modules,
and accepting small imperfections in screen display.

If you have any doubts about whether a CRT is defective, contact
Apple Technical Support.