Apple 20 User Manual
K
Service Source
Apple Multiple Scan 20
Display
Apple Multiple Scan 20 Display
Apple Multiple Scan 20 Display, Rev. B
K
Service Source
Basics
Apple Multiple Scan 20 Display
Basics Version Differences - 2
Version Differences
Overview
The Apple Multiple Scan 20 Display and Apple Multiple Scan
20 Display Rev. B have the same overall appearance.
However, the Rev. B version offers improved performance
and better screen resolution.
To distinguish the two versions, check the last three digits of
the serial number. The serial number for the Rev. B version
ends in one of the following:
• 5B4
• 5J2
• 5JE
• 5JF
Basics Version Differences - 3
Multiple Scan 20 Display
Dot pitch 0.31 mm.
Multiple Scan 20 Display, Rev. B
Dot pitch 0.26 mm.
Requires Rev. B parts for Main Deflection Board,
Microprocessor Controller Board, and Power Supply.
As you go through this manual, consider the information
applicable to both versions unless specified otherwise.
Basics Monitor Distortion - 4
Monitor Distortion
Overview
All large-screen monitors are susceptible to distortions
caused by environmental conditions. These distortions are
usually not visible on monitors with smaller screens.
Important:
appear distorted when set up in a new environment.
Common environmentally caused distortions are shown on
this and the following cards. Always check first for
environmental causes before attempting to exchange or
adjust a monitor with a distorted raster.
Ê
Even monitors set to factory specifications may
Basics Monitor Distortion - 5
Ideal Raster
Raster Shifted Up
and Left
Raster Shifted Up
and Right
Basics Monitor Distortion - 6
Environmental Influences
The following environmental conditions may distort the
raster:
• Proximity to metal objects, such as metal desks, file
cabinets, and bookshelves. Metal objects affect the
earth’s magnetic field. Earth magnetism usually distorts
only the edges of the screen.
• Fluorescent lights, other monitors, or electronic
appliances such as coffee makers and copy machines.
These objects cause dynamic raster distortion, that is,
movement or jitter of the image.
Basics - 7
Right Edge Not Straight
Left Side Bowed Out Right Side Bowed In
Basics - 8
Troubleshooting
Important:
environmental distortion problems.
Note:
go ahead and adjust it using the user controls. However, keep
in mind that if you then move the monitor you may need to
readjust the centering controls.
Before adjusting a monitor with a distorted raster, try the
following:
• Swivel or move the monitor, or
• Remove the monitor from the building and recheck it in
another location.
Exchanging the monitor cannot correct
If the monitor has shifted up/down or right/left only,
Basics - 9
If the display changes (for better or worse) when you move
it to another location, the environment is the source of the
problem. Relocate your monitor or remove the distortioncausing object.
If the display does not change when you move it to another
location, continue troubleshooting the problem (refer to
Troubleshooting).
Basics - 10
Upper-Right Corner Rounded
Left Edge S-Shaped Raster Tilted Right
Basics EEPROM Settings - 11
EEPROM Settings
Caution:
EEPROM settings before you replace the microprocessor
board.
See Troubleshooting for instructions on saving the EEPROM
settings from the old microprocessor board and restoring
the settings on the new microprocessor board.
If the settings are lost before they can be written to the new
EEPROM, the display will be impossible to repair, and the
whole display will need to be replaced.
To prevent data loss or corruption, always save
Basics EEPROM Settings - 12
Microprocessor Board
K
Service Source
Specifications
Apple Multiple Scan 20 Display
Specifications Characteristics - 1
Characteristics
Picture Tube
Screen Resolution
Scan Rates
Cable Connector
20-in. diagonal Trinitron CRT (19.1-in. viewable image)
Multiple scan
Bonded glass panel with antiglare/antistatic multilayer coating
640x480 to 1280x1024
0.31-mm stripe pitch
0.26-mm stripe pitch for Multiple Scan 20 Display, Rev. B
Vertical refresh range: 50 to 150 Hz
Horizontal scan range: 29 to 82 kHz
Macintosh, VGA, SVGA, and VESA compatible
15-pin miniature D-type
Specifications Characteristics - 2
Video Input Signals
System Requirements
Video: red, green, and blue analog signals; RS-343A
standard;.714 V peak to peak; positive going
Sync on green: RS-343A compatible level;.286 V ± 10%
negative-going during blanking intervals
Separate Sync: 1 to 5 V peak to peak; negative or positive going
Composite Sync: 1 to 5 V peak to peak; negative or positive going
Power Macintosh, Macintosh Centris, Macintosh Quadra, or any
NuBus compatible Macintosh with a Macintosh Display Card
24AC.
Macintosh II family, PowerBooks, Duo and Mini Dock, Macintosh
Performa, Macintosh LC, LC II, LC III, and Macintosh
computers with Display Cards 4•8, 8•24, 8•24GC work in
640x480 mode. Other modes possible with additional adapters.
System software version 7.1 or later
Specifications Controls and Ports - 3
Controls and Ports
User Controls
I/O Ports
Front panel: power, reset, and control buttons; brightness and
contrast controls
Additional controls available using the command button: horizontal
and vertical shift, horizontal and vertical size, rotation,
horizontal and vertical convergence, and color temperature
Automatic degauss at power on; manual degauss by turning power
switch off, then on (capable of full degauss after monitor is
turned off for 20 minutes or more)
Two Apple Desktop Bus (ADB) ports and one ADB pass-through
port
Specifications Physical and Electrical - 4
Physical and Electrical
Power Supply
Size and Weight
Universal power supply
Voltage: 90–132 and 198–264 VAC, self-configuring
Frequency: 47–63 Hz
Power: 165 W maximum (less than 15 W in energy-saver mode)
Height: 18.5 in. (474 mm)
Width: 18.5 in. (474 mm)
Depth: 19.6 in. (501.5 mm)
Monitor weight: 66 lb. (30 kg)
Fully boxed weight: 80 lb. (36 kg)
Specifications Physical and Electrical - 5
Monitor Stand
Built-in, tilt-and-swivel stand; tilt: -5 to +15°; swivel range:
±45° minimum
Three ADB ports (two ADB ports are in the front of the stand and
one ADB port is at the rear of the stand)
Specifications Environmental - 6
Environmental
Temperature
Altitude
Humidity
Power Savings Feature
Operating: 50°F to 104°F (10°C to 40°C)
Storage: 32°F to 140°F (0°C to 60°C)
Shipping: -4°F to 140°F (-40°C to 60°C)
Operating: to 10,000 ft. (1,067 m)
Shipping: to 35,000 ft. (3,048 m)
Operating: 10-80% maximum, noncondensing
Storage: 5-90% maximum, noncondensing
Shipping: 5-95% maximum, noncondensing
Conforms to the Energy Star Program of the United States
Environmental Protection Agency
K
Service Source
Troubleshooting
Apple Multiple Scan 20 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.)
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 First Checklist - 2
First Checklist
Important:
modules returned for repair are found to be fully operational.
Read this checklist before you return a module. Prevent needless
module replacement and unnecessary time delays.
Over 60% of the Apple Multiple Scan 20 Display
The Apple Multiple Scan 20 Display is not fully
compatible with all Macintosh computers and
PowerBooks.
If you suspect a loss of functionality, especially with the number
of screen resolutions available (in Control Panels), check the
Tech Info Library or contact Apple Technical Support.
Troubleshooting First Checklist - 3
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.
Move the unit to another room or building to help determine if
external interference is the source of the problem.
Troubleshooting First Checklist - 4
A misadjusted 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 replacements 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.
Troubleshooting Display Setting Restoration/Connect the Hardware - 5
Display Setting Restoration
Each Multiple Scan 20 Display has an EEPROM (located on the
microprocessor controller board) that contains adjustment
information specific to that monitor. Before you replace the
microprocessor board, save this EEPROM information.
Use MacTest Pro Display Setting Restore Utility to preserve the
monitor adjustment settings.
Connect the Hardware
There are two ways to connect the hardware to use the MacTest Pro
Display Setting Restore Utility:
1 Connect a serial cable (MINI DIN-8) between the
malfunctioning display and a separate computer running
MacTest Pro. Use either the modem port or the printer port
on the computer. (If you use the printer port, AppleTalk
Troubleshooting Display Setting Restoration - 6
must be turned off). Also connect a power cable to the display.
Advantage:
or quit MacTest Pro to complete the repair.
You do not have to shut down the host computer
Disadvantage:
computer (with display).
2 Connect the display as usual, using a video cable and power
cable. Also, connect a serial cable (MINI DIN-8) between the
display and either the modem or printer port on the
computer.
Advantage:
display under repair is the only display required.
Disadvantage:
needs to be replaced, the display may not be working well
enough to view this utility in MacTest Pro.
Another disadvantage is that after creating the data file from
This method requires a separate host
This method lends itself to on-site repair; the
Since the microprocessor board on the display
Troubleshooting Display Setting Restoration/Save the EEPROM Information - 7
the old EEPROM, you must quit MacTest Pro and shut down
the computer to install the new EEPROM.
Save the EEPROM Information
To save information from the old EEPROM, create a data file:
1 Start MacTest Pro.
2 Choose “Apple Multiple Scan 20 Display.”
3 Select “Test.”
4 Click “Create File.”
Install the Microprocessor Board
See Take Apart for instructions on installing the new
microprocessor board.
Troubleshooting Display Setting Restoration/Restore the EEPROM Information -
After the new microprocessor board is installed, the new EEPROM
will have default settings that allow you to read the display, but
with difficulty. When the settings from the old EEPROM are
transferred to the new EEPROM, the display should be clear and
the last color temperature mode chosen restored.
Restore the EEPROM Information
To download the saved adjustment information to the new EEPROM,
1 Start MacTest Pro.
2 Choose “Apple Multiple Scan 20 Display.”
3 Select “Test.”
4 Click “Write File.”
Troubleshooting Display Setting Restoration - 9
Caution:
important information about the EEPROM data file. If data is lost
or corrupted, you will have to return the display to Apple for
repair.
• Make sure that the data in the saved file is written back to the
• Make sure that the data file is deleted after writing the data
• Do not delete the new data file before it’s written to the new
Make certain that you are aware of the following
display used to create the file. Each display is unique, so
writing the wrong data to a display may cause severe
adjustment problems.
back to the display. This erasure ensures that data from one
display is not accidentally written to another.
EEPROM. If the file is lost before the data can be written to the
new EEPROM, the repair will be impossible to complete and the
whole display will need to be returned.
Loading...