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Apple Multiple Scan 15 AV
Display
K
Service Source
Basics
Apple Multiple Scan 15AV
Display
Basics Overview - 1
Overview
The Apple Multiple Scan
15AV Display is a 15-inch
(13.75-inch viewable
image size) color monitor
that supports a variety of
resolutions and that features
a built-in amplifier and
front-facing stereo
speakers.
Basics Overview - 2
Monitor Features
Features of the Apple Multiple Scan 15AV Display include
the following:
• Antistatic, antiglare screen surface
• Multiple screen resolutions ranging from 640x480 to
1024x768
• Front-facing, CD-quality speakers
• Easy-access front headphone jack
• Support for Mac OS and Windows 95
• Compatible with Apple ColorSync software for the
closest possible color match between what is seen on the
monitor and what is printed or scanned
Basics Repair Issues - 3
Repair Issues
The current configuration of the CRT/video board and the CRT ground strap differs from
the original configuration. The differences affect the CRT/video board removal procedure
in the Take Apart chapter, but they do not affect the performance of the display.
Note the differences in the following table:
Part Original Configuration Newer Configuration
CRT/Video Board Two prongs on CRT/video
board shield for connection to
two-wire connector from
CRT ground strap
CRT Ground Strap
connection to
CRT/Video Board
Two-wire connector at end of
two twisted wires from CRT
ground strap
Clip on CRT/video board shield
for connection to spade lugtype connector from CRT
ground strap
Spade lug-type connector at
end of single braided cable
from CRT ground strap
Note:
Apple part number 076-0757 is a kit that includes the new configuration of the
CRT/video board and a matching CRT ground strap with the lug-type connector. If your
display already has a CRT ground strap with the lug-type connector, you do not need to
replace the CRT ground strap. Otherwise, refer to “CRT Ground Strap” in the Take Apart
chapter in this manual for replacement instructions.
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Service Source
Specifications
Apple Multiple Scan 15AV
Display
Specifications Characteristics - 1
Characteristics
Picture Tube
Phosphor
15-in. CRT (13.75-in. diagonal viewable image size)
Raster Size: 10.6 in. x 7.9 in. (270 mm x 200 mm)
Multiple scan
Antistatic, antiglare surface treatment
Dot Pitch: 0.28 mm
White Point: 9300° K
Shipping Brightness: 25 foot Lamberts (± 5 fL)
Aluminized P22 (red, green, blue)
Phosphor CIE Coordinates:
Red x = 0.610 ± 0.020 y = 0.342 ± 0.020
Green x = 0.298 ± 0.020 y = 0.588 ± 0.020
Blue x = 0.151 ± 0.015 y = 0.064 ± 0.015
Specifications Characteristics - 2
Screen Resolution
Macintosh
PC-Compatibles
640x480 at 60 Hz in VGA mode
640x480 at 67 Hz in Macintosh mode
800x600 at 60 Hz in SVGA mode
800x600 at 72 Hz in SVGA mode
832x624 at 75 Hz in Macintosh mode
1024x768 at 60 Hz in Macintosh mode
1024x768 at 70 Hz in Macintosh mode
1024x768 at 75 Hz in Macintosh mode
640x480 at 60 Hz in VGA mode
800x600 at 60 Hz in SVGA mode
800x600 at 72 Hz in SVGA mode
1024x768 at 60 Hz in SVGA mode
1024x768 at 70 Hz in SVGA mode
1024x768 at 75 Hz in SVGA mode
Specifications Characteristics - 3
Cable Connector
Input Signals
Audio
15-pin miniature D-type
Red, green, and blue signals; separate sync
Response: 50 Hz to 20,000 Hz
Output: 2 W
SPL: 82 db @ 1 kHz, 1 meter
Specifications Characteristics - 4
System Requirements
Power Macintosh, Macintosh Centris, Macintosh Quadra, some
Macintosh Performas, or any NuBus compatible Macintosh
with a Macintosh Display Card 24AC.
Macintosh II family, PowerBooks, Duo and Mini Dock, some
Macintosh Performa, Macintosh LC, LC II, LC III, and
Macintosh computers with Display Cards 4•8, 8•24, or
8•24GC installed work in 640x480 mode. Other modes
possible with additional adapters.
System software version 7.1 or later
Specifications Characteristics - 5
Monitor Timings
640x480
Resolution @ 60 Hz
Horizontal Timing Horizontal Timing
Back Porch: 48 dots Back Porch: 96 dots
H SYNC: 96 dots H SYNC: 64 dots
Front Porch: 16 dots Front Porch: 64 dots
1 dot: 39.72 ns 1 dot: 33.06878 ns
1 H: 31.77 µs 1 H: 28.5714 µs
1/dot: 25.175 MHz 1/dot: 30.24 MHz
Vertical Timing Vertical Timing
Back Porch: 33 H Back Porch: 39 H
V SYNC: 2 H V SYNC: 3 H
Front Porch: 10 H Front Porch: 3 H
1/H: 31.5 kHz 1/H: 35.0 kHz
1 V: 16.67 ms 1 V: 15.0 ms
640x480
Resolution @ 67 Hz
Specifications Characteristics - 6
Monitor Timings
800x600
Resolution @ 60 Hz
Horizontal Timing Horizontal Timing
Back Porch: 88 dots Back Porch: 64 dots
H SYNC: 128 dots H SYNC: 120 dots
Front Porch: 40 dots Front Porch: 56 dots
1 dot: 25.0 ns 1 dot: 20.0 ns
1 H: 26.4 µs 1 H: 20.800 µs
1/dot: 40.0 MHz 1/dot: 50.0 MHz
Vertical Timing Vertical Timing
Back Porch: 23 H Back Porch: 23 H
V SYNC: 4 H V SYNC: 6 H
Front Porch: 1 H Front Porch: 37 H
1 H: 37.879 µs 1/H: 48.077 kHz
1/H: 16.58 kHz 1 V: 13.853 ms
1 V: 16.58 ms
800x600
Resolution @ 72 Hz
Specifications Characteristics - 7
Monitor Timings
832x624
Resolution @ 75 Hz
Horizontal Timing Horizontal Timing
1/H: 49.7 kHz Back Porch: 160 dots
Back Porch: 224 dots H SYNC: 136 dots
H SYNC: 64 dots Front Porch: 24 dots
Front Porch: 32 dots 1 dot: 15.385 ns
1 H: 20.1 µs 1 H: 20.677 µs
1/dot: 57.28 MHz 1/dot: 65.0 MHz
Vertical Timing Vertical Timing
Back Porch: 38 H Back Porch: 29 H
V SYNC: 3 H V SYNC: 6 H
Front Porch: 2 H Front Porch: 3 H
1 V: 13.41 ms 1/H: 48.363 kHz
1024x768
Resolution @ 75 Hz
1 V: 16.667 ms
Specifications Controls and Ports - 8
Controls and Ports
User Controls
I/O Ports
Front Panel: power, select, up, down, recall, brightness,
contrast, sound volume
Additional picture controls available using the select button:
horizontal and vertical shift, horizontal and vertical size
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)
Headphone/Speaker: one input port and one pass-through output
port
Specifications Physical and Electrical - 9
Physical and Electrical
Power Supply
Input Frequency Range
Size and Weight
Monitor Stand
Voltage: 100–240 VAC
Frequency: 50–60 Hz
Power: 75 W maximum; 8 W sleep mode
Horizontal: 30 kHz to 60.2 kHz
Vertical: 56 Hz to 75 Hz
Height: 14.93 in. (383 mm ± 5 mm)
Width: 17.3 in. (443 mm ± 5 mm)
Depth: 15.4 in. (395 mm ± 5 mm)
Weight: 31 lb. (14 kg)
Removable tilt-and-swivel stand
Specifications Environmental - 10
Environmental
Temperature
Humidity
Altitude
Power Saving Feature
Operating: 50°F to 104°F (10°C to 40°C)
Shipping: –4°F to +151°F (–40°C to +65°C)
Storage: 32°F to 140°F (0°C to 60°C)
20% to 95% (noncondensing) over the range of 77°F to 104°F
(25°C to 40°C)
Operating: 0 to 10,000 ft. (0 to 3,048 m)
Transit: 0 to 15,000 ft. (0 to 4,500 m)
Conforms to the Energy Star Program of the United States
Environmental Protection Agency
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Service Source
Troubleshooting
Apple Multiple Scan 15AV
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:
returned for repair are found to be fully operational. Read this
checklist before you return a module, and prevent needless module
replacement and unnecessary time delays.
Many Apple Multiple Scan 15AV display modules
The Apple Multiple Scan 15AV 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.
For more information on what computers or video cards are
compatible with the display, see the Specifications chapter.
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 (such as desks or file
cabinets). 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 using 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
main 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.
Troubleshooting Symptom Charts/No Raster - 4
Symptom Charts
No Raster
No raster (screen is
black); power
indicator light on
No raster; power
indicator light off
Display has one
predominant color
1 Ensure that the display is connected to a known-good video
source.
2 Adjust the front panel brightness and contrast controls.
3 Check the monitor’s video cable for breakage or damage.
Perform a continuity check to ensure that the video cable is
not at fault.
4 Slowly adjust the screen control on the flyback transformer
to see if the raster appears. If it reappears, perform the
“Cutoff and White Balance” procedure in the Adjustments
chapter.
5 Replace the main deflection board.
1 Ensure that the display is plugged in and that the power cord
is not damaged.
2 Replace the main deflection board.
Video
1 Verify that the CRT/video board is connected securely to the
CRT socket.
2 Inspect the video cable connector (at P301) on the CRT/
video board for breakage/continuity. This cable carries the
Red, Green, and Blue signals from the main deflection board
to the CRT/video board.
P301
3 Perform the “Cutoff and White Balance” procedure in the
Adjustments chapter.
4 Replace the CRT/video board.
5 If you suspect a defective CRT, contact Apple Technical
Support.
Troubleshooting Symptom Charts/Video
(Continued)
- 5
Areas of the screen
have blotches of color
Screen is too bright;
adjusting Brightness
control does not
lower intensity
Video
1 Since this type of problem (purity) is often caused by
2 Turn off the monitor power switch, wait five minutes, then
3 Severe magnetic field problems require the use of an
1 Perform the “Cutoff and White Balance” procedure in the
2 Replace the CRT/video board.
3 Replace the main deflection board.
4 If you suspect a defective CRT, contact Apple Technical
(Continued)
magnetic fields in the area, place unit in another location to
see if symptom disappears, changes in its intensity, or
changes location on the screen.
turn it back on. This enables the monitor’s internal
degaussing coil.
external degaussing coil. (Degaussing coils can be purchased
at most larger electronic parts stores.)
Adjustments chapter.
Support.
Troubleshooting Symptom Charts/Geometry - 6
Geometry
Raster not centered 1 Adjust either or both horizontal center and vertical center
controls. See “Geometry” in the Adjustments chapter.
2 Adjust the horizontal center switch (SW701 on version G
only). See “Horizontal Centering” in the Adjustments
chapter.
Size of the horizontal
and/or vertical
raster is incorrect
One or both sides of
the raster is bowed
Raster is narrower or
wider at the top of the
screen than at the
bottom
Use the appropriate size controls to set the vertical height to 200
mm (7.9 inches) and the horizontal width to 270 mm (10.6
inches). Refer to “Geometry” in the Adjustments chapter.
1 To minimize the bowing, perform the “Pincushion”
procedure in the Geometry section of the Adjustments
chapter. Keep in mind that there is some allowed tolerance
and the setting will NOT always be perfect.
2
Important:
is still considered to be within tolerance. If you have any
doubts, contact Apple Technical Support before replacing a
board that may not fix the problem.
3 Replace the main deflection board.
1 To set the keystone control for optimum screen performance,
perform the “Keystone” procedure in the Geometry section
of the Adjustments chapter. Keep in mind that there is some
allowed tolerance and the setting will NOT always be perfect.
2
Important:
imperfection is still considered to be within tolerance. If you
have any doubts, contact Apple Technical Support before
replacing a board that may not fix the problem.
3 Replace the main deflection board.
As mentioned in step one, some degree of bowing
As mentioned in step one, some trapezoidal
Troubleshooting Symptom Charts/Sound Problems - 7
Sound Problems
Distorted or no sound
coming through one
speaker
Distorted or no sound
in both speakers
On a Performa 6400,
sound comes through
Performa subwoofer
even though
headphones are
plugged into
headphone jack on
front of display
Disconnect the wires to both speakers. Using jumper cables,
connect the right speaker wire to the left speaker and the left
speaker wire to the right speaker. This will isolate the problem to
a defective speaker or a defective main deflection board.
1 Try another sound source to ensure that you are not using a
defective CD or other sound device.
2 Replace the main deflection board.
To mute the subwoofer, do any one of the following:
• Keep headphones plugged into headphone jack on front of
display, but mute subwoofer using Sound and Displays
Control Panel.
• Keep headphones plugged into headphone jack on front of
display, but lower volume of subwoofer by turning balance
control knob at rear of Performa 6400 fully
counterclockwise.
• Plug headphones into headphone jack on front of Performa
6400.
• Plug headphones into headphone jack at rear of Performa
6400.
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Service Source
T ak e Apart
Apple Multiple Scan 15AV
Display
Take Apart Safety Guidelines for Taking Apart the Apple Multiple Scan 15AV
CRT Discharge Tool
Anode Cap
Safety Guidelines for Taking Apart the
Apple Multiple Scan 15AV Display
±
Warning:
vacuum picture tube. To prevent serious injury, review
CRT safety in Bulletins/Safety.
±
Warning:
discharging the CRT and setting up an ongoing ground
connection.
Important:
and before replacing a module, you must
1 Discharge the CRT and remove the anode cap.
2 Establish an ongoing ground by using a cable with
alligator clips at both ends. Connect one end to the anode
aperture, and connect the other end to the braided ground
strap that wraps around the CRT.
This product contains high voltage and a high-
Never use a grounding wriststrap until after
Whenever the housing of the monitor is removed
The ground strap
Note:
and CRT/video board on
newer displays are
somewhat different than
pictured here. Refer to
“Repair Issues” in the
Basics chapter for details.
3 With the CRT discharged and the ongoing ground in place,
wear a grounding wriststrap to prevent equipment
damage from static electricity.
Ongoing GroundAnode Aperture
Ground Strap
Take Apart Control Panel Door - 2
Control Panel Door
No preliminary steps are
required before you begin
this procedure.
Control Panel Door
Take Apart Control Panel Door - 3
1 Position the monitor
close to the edge of a
table and so that the
screen faces you.
2 Press down on the center
of the door so it flips
open.
Take Apart Control Panel Door - 4
3 Grasp each side of the
door and pull the door
down to release it from
its hinges.
Control Panel Door
Replacement Note:
Position
the door under the bezel so
the hinges line up with the
bezel contacts. Push the door
onto the bezel until it snaps
into place.
Take Apart Tilt-Swivel Stand - 5
Tilt-Swivel Stand
Before you begin, remove
the control panel door.
Note:
Because this
procedure requires you to
place the monitor face
down, you need to remove
the control panel door to
prevent damaging it.
Tilt-Swivel
Stand
Take Apart Tilt-Swivel Stand - 6
1 Place the monitor face-
down on a padded surface
with the bottom of the
stand facing you.
2 Press inward on both
tabs on the sides of the
stand.
Tilt-Swivel Stand
TabTab
Take Apart Tilt-Swivel Stand - 7
3 Tilt the stand upward and
Tilt-Swivel Stand
HookHook
off the bottom housing.
Replacement Note:
With the
monitor face down, insert
the two hooks on the back of
the tilt-swivel stand into
the two slots on the bottom
housing. Push the stand onto
the housing until its tabs
snap into place.
Take Apart Rear Housing - 8
Rear Housing
Rear
Housing
Before you begin, remove
• Control panel door
• Tilt-swivel stand
±
Warning:
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review CRT safety in
Bulletins/Safety and read
the safety guidelines at the
beginning of this chapter.
This product
Take Apart Rear Housing - 9
1 Place the monitor face-
down on a padded surface.
2 Remove the four Phillips
screws (two on each
side).
Screws
Take Apart Rear Housing - 10
3 Lift the rear housing
straight off the CRT
Rear
Housing
assembly and route the
video cable through the
opening in the rear
housing.
Video Cable
Take Apart Speaker - 11
Speaker
Speakers
Before you begin,
• Remove the control panel
door
• Remove the tilt-swivel
stand
• Remove the rear housing
• Discharge the CRT
±
Warning:
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review CRT safety in
Bulletins/Safety and read
the safety guidelines at the
beginning of this chapter.
This product
Take Apart Speaker - 12
1 Locate the inoperative
speaker and disconnect
the speaker connector
near the display’s
bottom corner, either
• Red speaker connector
on the right
• White speaker
connector on the left
Speaker Connectors
Take Apart Speaker - 13
2 Remove the speaker wire
from its routing channel.
Routing
Channel
Speaker Wire
Take Apart Speaker - 14
3 Use a flat-blade
screwdriver to pry off
the speaker and its foam
Screwdriver
gasket from the bezel.
4 Lift the speaker from the
Foam Gasket
inside bezel.
Speaker
Replacement Note:
When
replacing a speaker, verify
that the bezel is clean, peel
off the foam gasket’s
adhesive backing, and apply
the speaker to the bezel.
The speakers are fully
interchangeable, so you can
replace a speaker on either
side of the bezel.
Take Apart Speaker Grilles - 15
Speaker Grilles
Speaker Grille Speaker Grille
Before you begin,
• Remove the control panel
door
• Remove the tilt-swivel
stand
• Remove the rear housing
• Discharge the CRT
±
Warning:
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review CRT safety in
Bulletins/Safety and read
the safety guidelines at the
beginning of this chapter.
This product
Take Apart Speaker Grilles - 16
Bezel
Screw
Screw
1 Remove the two recessed
screws at the top and
bottom of the inner bezel
sides.
Caution:
Do not remove
the CRT corner screws.
Take Apart Speaker Grilles - 17
Screwdriver
Bezel
Speaker
Grille
2 Insert a small flat-
blade screwdriver
between the outside
speaker grille and bezel.
Pry off the grille in four
places to release the four
side tabs.
Take Apart Speaker Grilles - 18
3 Gently tilt the speaker
Hook
grille toward the
display face to release it
from the bezel hooks.
4 Repeat steps 1 through 3
for the other speaker
grille.
Hook
Replacement Note:
The left
and right speaker grilles
come as a pair and are not
interchangeable.
Take Apart Sound In Board - 19
Sound In Board
Before you begin,
• Remove the control panel
door
• Remove the tilt-swivel
stand
• Remove the rear housing
• Discharge the CRT
±
Sound In
Board
Warning:
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review CRT safety in
Bulletins/Safety and read
the safety guidelines at the
beginning of this chapter.
This product
Take Apart Sound In Board - 20
1 Remove
• Two screws
• P156 connector
2 Lift the board off the
metal bracket.
Screw Sound In
Board
Screw
P156
Take Apart CRT/Video Board - 21
CRT/Video Board
CRT/Video Board
Before you begin,
• Remove the control panel
door
• Remove the tilt-swivel
stand
• Remove the rear housing
• Discharge the CRT
±
Warning:
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review CRT safety in
Bulletins/Safety and read
the safety guidelines at the
beginning of this chapter.
This product
Take Apart CRT/Video Board - 22
CRT Shield
Ground CableGround Cable
Caution:
When
disconnecting cables from
the CRT/video board, be
careful not to apply
excessive pressure on the
neck of the CRT.
1 Disconnect the two
braided CRT ground
cables located on both
sides of the CRT shield.
Take Apart CRT/Video Board - 23
2 From the side of the CRT
assembly, disconnect
• Two-wire connector
behind CRT/video
board (On newer
displays the two-wire
connector was
replaced by a braided
cable with a spade
lug-type connector.)
• Braided cable at E2 to
the right of the
flyback transformer
on the main deflection
board
Connector
Braided Cable at E2Two-Wire
Take Apart CRT/Video Board - 24
3 From the back of the CRT
assembly, remove
• Phillips screw that
connects the braided
cable to the sound in
board
• Phillips screw that
attaches the braided
cable to the back
panel flange
ScrewScrew
Take Apart CRT/Video Board - 25
Red Wire at P304
Two-Wire Connector at P305
4 From the side of the CRT
assembly, disconnect
• Red wire with the
gray connector on the
CRT/video board at
P304
• Black two-wire
connector on the CRT/
video board at P305
Take Apart CRT/Video Board - 26
5
Neck
Caution:
bending, or applying
Twisting,
force to the CRT/video
board could damage the
neck of the CRT.
With a gentle side-toside motion, ease the
CRT/video board off the
neck of the CRT until it
clears the neck pins.
6 With some wires still
attached, set the CRT/
video board on the table.
CRT/Video
Board
Take Apart CRT/Video Board - 27
Screw
P301
P302
7 Using a Phillips
screwdriver, remove
the screw holding the
braided cable to the back
panel flange.
8 Disconnect
• Connector P302
• Connector P301
Take Apart CRT/Video Board - 28
Lock
Screwdriver
CRT Socket
9 Use a flat-blade
jeweler’s screwdriver
to gently pry up the wire
lock (about one to two
millimeters) from the
CRT socket base.
Note:
On newer displays
the lock is not present.
Take Apart CRT/Video Board - 29
10 Using needlenose pliers,
firmly grasp the lock
and twist it in a
clockwise direction
(about one-eighth of a
turn) while pulling the
lock straight up.
Note:
On newer displays
where the lock is not
present, firmly grasp
the wire and twist it in a
clockwise direction
three to four turns. Pull
the wire straight up.
LockNeedlenose Pliers
Take Apart CRT/Video Board - 30
11 Pull the wire lock and
wire from the CRT
socket.
Lock CRT Socket
Because the lock fits
loosely over the wire,
slightly bend the wire
so the lock cannot slide
off.
Replacement Note:
Before
securing the lock inside the
CRT socket, ensure the end
of the wire is straight. With
the lock attached, push the
wire straight down as far as
it will go. Then secure the
lock in the socket with a
counterclockwise turn.
Take Apart CRT/Video Board - 31
Replacement Note:
newer displays the wire lock
is not present and the wire
receptacle on the CRT socket
is smaller. To replace the
wire, ensure the end of the
wire is straight and push it
down as far as it will go.
Gently tug on the wire to
ensure a secure fit.
On
Take Apart CRT/Video Board - 32
Screw
Shield
Screw
Replacement Note:
Before
returning a CRT/video board
for replacement, remove and
retain the shield so you can
attach it to the replacement
board.
Remove the two Phillips
screws that secure the
shield onto the CRT/video
board.
Take Apart CRT/Video Board - 33
CRT Ground Strap
Replacement Note:
replacing the CRT/video
board, you might need to
replace the CRT ground
strap as well. Check the
ground connection on the
CRT/video board shield and
the connector on the CRT
ground strap. The
connections must match.
Refer to “Repair Issues” in
the Basics chapter for more
details.
When
Take Apart CRT/Video Board - 34
Removing the Old CRT
Ground Strap
1 Place the display face-
down on a thick book that
is slightly smaller than
the dimensions of the
display face.
Note:
The graphic at left
shows the original ground
strap configuration with the
two-wire connector. If you
have installed a new CRT/
video board, use the
replacement ground strap
included in the CRT/video
board kit (Apple part
number 076-0757).
Take Apart CRT/Video Board - 35
2 Cut the four plastic cable
ties that secure the CRT
ground strap to the
degauss coil.
3 Remove the four CRT
corner screws and
washers; ensure the
rubber grommets
remain in the corner
tabs.
Take Apart CRT/Video Board - 36
4 Starting at the top
corner of the CRT, lift
off the end loop of the
ground strap from the
corner tab. Repeat for
the other three loops.
5 Remove the old CRT
ground strap from the
display assembly.
Take Apart CRT/Video Board - 37
Installing the New CRT
Ground Strap
1 Locate the lug-type
connector on the new
ground strap. Starting
at that end, slip the end
loop over the top left
corner tab.
2 Locate the loop that is
connected with a
spring. Slip the spring
loop over the bottom left
corner tab, as shown.
Ensure the rubber
grommets remain in
place in the corner tabs.
Take Apart CRT/Video Board - 38
3 Route the rest of the
strap to the other side of
the CRT in between the
CRT yoke and the main
deflection board. Ensure
the CRT ground strap
slips beneath the degauss
coil.
4 Attach the remaining two
loops over the corner
tabs.
5 Ensure the rubber
grommets remain in the
corner tabs. Lift up and
support the bezel
assembly to secure the
four corner screws.
Take Apart CRT/Video Board - 39
6 Ensure the CRT ground
strap maintains contact
with the CRT on all three
sides and the degauss coil
is centered on the CRT.
Adjust as necessary.
7 Using the plastic cable
ties included with the
ground strap in the CRT/
video board kit, secure
the ground strap to the
degauss coil at the two
top corners. Use the
remaining two cable ties
to secure the ground
strap to the middle of the
degauss coil.
Take Apart Video Cable - 40
Video Cable
Before you begin,
• Remove the control panel
door
• Remove the tilt-swivel
stand
• Remove the rear housing
• Discharge the CRT
±Warning: This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review CRT safety in
Bulletins/Safety and read
the safety guidelines at the
Video Cable
beginning of this chapter.
Take Apart Video Cable - 41
Ground Cable Ground Cable
Two-Wire
Connector
CRT/Video Board
Two-Wire
Connector
Caution: Twisting, bending,
or applying force to the
CRT/video board could
damage the neck of the CRT.
1 Disconnect
• Two braided CRT
ground cables from
the CRT shield
• Two two-wire
connectors from the
CRT/video board
2 With a gentle side-to-
side motion, ease the
CRT/video board off the
neck of the CRT until it
clears the neck pins.
Take Apart Video Cable - 42
3 With some wires still
Cable Clip
ScrewGround Screw
attached, move the CRT/
video board so that you
can reach the back panel
screws.
4 Remove
• Phillips ground screw
and lock washer
• Phillips screw and
lock washer at the
cable clip
Take Apart Video Cable - 43
5 Disconnect
• Connector P301
• Pin E3
P301 E3
Take Apart Video Cable - 44
6 Disconnect P401 from
the center of the main
deflection board.
7 Cut the tie wrap that
holds the P401 cable.
8 Remove the cable from
the cable clamp.
Replacement Note:
Secure the P401 cable
by routing it through the
cable clamp and using a
new wire tie wrap.
Cable Clamp
Tie Wrap
P401
Take Apart Video Cable - 45
9 At the video cable strain
relief, press the two
hooks forward and pull
up on the video cable
strain relief to release it
from the slot.
Video Cable
Strain Relief
Hook Hook
Take Apart Main Deflection Board - 46
Main Deflection Board
Before you begin,
• Remove the control panel
door
• Remove the tilt-swivel
stand
• Remove the rear housing
• Discharge the CRT and
disconnect the anode cap
• Remove the CRT/video
board
Main Deflection
Board
Take Apart Main Deflection Board - 47
±Warning: This product
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review CRT safety in
Bulletins/Safety and read
the safety guidelines at the
beginning of this chapter.
1 Remove the Phillips
screw from the chassis
bracket (next to the
bottom right CRT corner
screw).
Screw
Take Apart Main Deflection Board - 48
2 Disconnect
• Speaker connector
• Ground pin
Ground Pin
Speaker
Connector
Take Apart Main Deflection Board - 49
3 Disconnect the CRT yoke
wire at P701.
P701
Take Apart Main Deflection Board - 50
4 Disconnect
• Speaker connector
• Degaussing coil at
P902
Speaker
Connector
P902
Take Apart Main Deflection Board - 51
5 Place the monitor face-
down on a padded surface.
6 Remove the two Phillips
screws from the bottom
housing.
Bottom
Housing
Screw
Screw
Take Apart Main Deflection Board - 52
7 While grasping the end
of the main deflection
board chassis with one
hand, use a flat-blade
Chassis
screwdriver to press in
on one of the two tabs on
the bottom of the bezel
assembly.
Press in on the other
tab, and slide the main
deflection board straight
up and off of the CRT
assembly.
8 Refer to this chapter to
remove the sound in
board, video cable, and
Screwdriver
TabTab
control panel board that
Take Apart Main Deflection Board - 53
are attached to the main
deflection board chassis.
Replacement Note: With the
control panel board secured
to the replacement main
deflection board, align the
side edges of the main
deflection board with the two
slide rails on the bottom
housing.
Ensure no cables get
pinched as you slide the
board into place. With the
board in place, be sure to
Slide Rails
Slide RailsBottom Housing
reconnect all cables
including the anode cap.
Take Apart Control Panel Board - 54
Control Panel Board
Before you begin,
• Remove the control panel
door
• Remove the tilt-swivel
stand
• Remove the rear housing
• Discharge the CRT
• Remove the CRT/video
board
• Remove the main
deflection board
±Warning: This product
Control Panel Board
contains high voltage and a
high-vacuum picture tube.
Take Apart Control Panel Board - 55
To prevent serious injury,
review CRT safety in
Bulletins/Safety and read
the safety guidelines at the
beginning of this chapter.
1 Remove the Phillips
screw.
Screw
Take Apart Control Panel Board - 56
2 Slightly tilt the control
panel board forward, and
slide it out of the plastic
holder.
Holder
Take Apart Control Panel Board - 57
3 Disconnect the following
four connectors:
• P152
• P153
• P154
• P155
Replacement Note: Remove
and retain the three knobs
from the control panel board
so you can attach them to the
replacement board.
P152 P153 P154 P155
Take Apart Power Switch - 58
Power Switch
Before you begin,
• Remove the control panel
door
• Remove the tilt-swivel
stand
• Remove the rear housing
• Discharge the CRT
• Remove the CRT/video
board
• Remove the main
deflection board
±Warning: This product
contains high voltage and a
Power Switch
high-vacuum picture tube.
To prevent serious injury,
Take Apart Power Switch - 59
review CRT safety in
Bulletins/Safety and read
the safety guidelines at the
Bottom Housing
beginning of this chapter.
1 Place the monitor face
down on a padded surface
so the bottom housing
faces you.
Take Apart Power Switch - 60
2 Locate the power switch
lock inside the bezel.
Lock
Bezel
Take Apart Power Switch - 61
3 Use needlenose pliers to
grasp the lower tab of
the power switch lock.
Pull up the lock as far as
it will go.
Tab Lock
Take Apart Power Switch - 62
4 While holding the lock
tab up, use a second pair
of needlenose pliers to
pinch the two side tabs
so that they fit through
the slot in the lock.
Slot
Repeat for the other side
tabs.
Side
Tab
Needlenose Pliers Needlenose Pliers
Tab
Take Apart Power Switch - 63
5 Pull the lock off of the
power switch and spring.
Power Lock
Switch
Spring
Take Apart Power Switch - 64
6 Tilt up the CRT assembly
to pull out the power
switch and spring from
the front side of the
bezel.
The power switch
assembly consists of the
three pieces shown here.
Lock
Spring
Power
Switch
Take Apart Front Bezel - 65
Front Bezel
Before you begin,
• Remove the control panel
door
• Remove the tilt-swivel
stand
• Remove the rear housing
• Discharge the CRT
• Remove the CRT/video
board
• Remove the main
deflection board
• Remove the speakers
• Remove the power switch
Front Bezel
Take Apart Front Bezel - 66
±Warning: This product
contains high voltage and a
high-vacuum picture tube.
Bottom Housing
To prevent serious injury,
review CRT safety in
Bulletins/Safety and read
the safety guidelines at the
beginning of this chapter.
1 Place the monitor face
down on a padded surface
so the bottom housing
faces you.
Take Apart Front Bezel - 67
2 Using a Phillips
screwdriver, remove
the four CRT corner
screws and washers (two
on each side).
Screw
Screw
Take Apart Front Bezel - 68
3 Using both hands, lift the
CRT off of the front
bezel.
CRT
Front Bezel
K
Service Source
Adjustments
Apple Multiple Scan 15AV
Display
Adjustments Power Supply Voltage - 1
Power Supply Voltage
Before you begin, refer to
the Take Apart chapter to
remove the rear housing.
±
Warning:
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review CRT safety in
Bulletins/Safety.
Note:
Perform the power
supply voltage adjustment
whenever the main
deflection board is replaced.
This product
Adjustments Power Supply Voltage - 2
1 Turn on the display and
let it warm up for five
minutes.
2 Using the control strip,
set the screen
resolution to 640x480.
3 Using the Display
Service Utility, select
the crosshatch display
pattern with the black
background from the
Standard Patterns
screen.
Adjustments Power Supply Voltage - 3
4 Locate jumper wire J5
on the left side of the
main deflection board.
J5
Adjustments Power Supply Voltage - 4
Positive Probe at J5
Voltmeter
Ground Probe at
Chassis
5 Connect the positive
probe (red wire) of a
digital voltmeter to
jumper J5 and connect
the ground probe (black
wire) to the metal
chassis.
Adjustments Power Supply Voltage - 5
6 While maintaining the
voltmeter probe
connections, use a
plastic screwdriver to
adjust VR951 until the
voltmeter reads 50 VDC
± 0.2V.
VR951Positive Probe at J5
Adjustments High Voltage - 6
High Voltage
Before you begin, refer to
the Take Apart chapter to
remove the rear housing.
±
Warning:
contains high voltage and a
high-vacuum picture tube.
To prevent serious injury,
review CRT safety in
Bulletins/Safety.
Note:
Perform the highvoltage adjustment
whenever the main
deflection board is replaced.
This product
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