Apple 20 User Manual

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Apple Multiple Scan 20
Display

Apple Multiple Scan 20 Display

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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
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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
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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.
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