A A
CP21
08979
TECHNICAL
SERVICE
DATA
FEATURES:
COMPLETE SCHEMATICS
•
PRELIMINARY SERVICE CHECKS
•
TROUBLESHOOTING TIPS
EASY-READ
WAVEFORMS
•
REPLACEMENT PARTS LISTS
•
SEMICONDUCTOR
CROSS-REFERENCE
5AM
5
COMPUTERFACTS"
ATARI
MODEL
1025
PRELIMINARY SERVICE
CHECKS
This
data
provides the
user
with
a
time-saving
service tool
which
is designed for quick isolation and repair of printer
malfunctions.
CM
O
cc
^
CM
O
Check all
interconnecting cables for
good
connection and
correct hook-up before making service
checks.
Replacement or repair of
CPU
board or connectors
may
be
necessary
after the malfunction has been isolated.
TEST EQUIPMENT
AND TOOLS
TEST EQUIPMENT
Digital
Volt/Ohm Meter
Scope
Logic Probe
TOOLS
Phillips Screwdriver
Small
Screwdriver
Low Voltage Soldering Iron
Desoldering Iron
REPLACEMENT
PARTS
AND
DESCRIPTION
ITEM
NO.
DESCRIPTION
D1 Diode, GP15B
D2 Diode, GP15B
D5 Diode, GP15B
D6
Diode, GP15B
F1
Fuse, 1.75A
@250V Fast Acting
F2 Fuse, 1.75A @250V Fast Acting
M1 Print Head
M2 Carriage Motor
M3 Line Feed Motor
OSC1
Crystal,
7.37MHz
Q1
IC,
HA17805P
Q8 IC, iP8051
T1 Power Transformer, 4LP-45191-137
SAMS
Howard
W. Sams
&
Co.
4300 West
62nd Street, P.O.
Box 7092,
Indianapolis, Indiana
46206
U.S.A.
The listing
of
any available
replacement part herein
does not
constitute
in
any
case a
recommendation, warranty or guaranty
by
Howard
W.
Sams
& Co.
as to the quality
and
suitability
of such
replacement
part. The
numbers of these
parts have been compiled
from information
furnished
to
Howard W. Sams
&
Co.
. by
the
manufacturers
of
the
particular
type
of
replacement
part
listed.
Reproduction
or
use, without express
permission, of editorial
or
pictorial
content, in
any manner, is prohibited.
No patent liability
is
assumed with
respect to the
use of
the information
contained herein.
vp)
1986 Howard
W. Sams
&
Co.
4300
West
62nd Street,
P.O. Box 7092, Indianapolis,
Indiana
46206 U.S.A.
Printed
in
U.S. of America
86CP14977
DATE
8-86
PRELIMINARY
SERVICE CHECKS
(Continued)
@
®@
'.'..:
PINS 18, 19
7.37MHz
Q8
10.5V
AIN
CONTROl
(2H)@)(4F
MISCELLANEOUS
ADJUSTMENTS
FIRST CHARACTER PRINTING
POSITION
ADJUSTMENT
Loosen screws fastening
Carriage Motor to
bottom cover.
Turn
motor assembly a
little one way or
the other so that
when the
power is
turned ON, the print
head
returns and
stops at the home sensor
position within
tolerance, see
Figure 1. If changing position of
motor assembly does
not
correct the print position, change the
engagement
position
of the carriage synchro-belt on the
pulley
by
one
or two
teeth.
1mm
1mm
I
CN10>-
#e
•
0.55-0.75mm
Home
Sensor
DETECTOR
LEVER
a
Figure
1
PLATEN/PAPER
SEPARATOR
ADJUSTMENT
Remove the upper
cover,
loosen the
paper
separator
screws. Adjust the
clearance
between
the
platen
and the
paper
separator for
approximately
0.5mm.
Tighten
the
paper separator
screws, see
Figure 2.
Figure
2
PRINTHEAD
ADJUSTMENT
Print head adjustment
should be
performed
after repair of
printer mechanism,
carriage
assembly
frame, or print head.
Loosen
carriage shaft
screws on
the sides of
the printer
mechanism. Move
carriage shaft
forward or
backward until
gap between
platen and print
head is
between 0.45mm and
0.5mm.
ATARI
MODEL
1025
©
©
PRELIMINARY
SERVICE
CHECKS
(Continued)
SERVICE
CHECKS
MATCH
THE
NUMBERS
ON THE
INTERCONNECTING
DIAGRAM AND
PHOTOS
WITH
THE
NUMBERS
ON
THE
SERVICE CHECKS
TO
BE PERFORMED.
POWER
SUPPLY
(A) If
the Printer
is dead check Fuse F2.
(B) Check
Diodes
D5
and
D6
for
shorts.
(C) If Diodes
D5 and D6 are good, check
Power
Transformer
(T1) by
substitution.
(D) Check
for
26V at anode of Diodes D26 and D46.
If 26V is
missing check Main Control Board
by
substitution.
(E) Check
for
5V
at pin 2 of
Regulator IC
(Q1),
if
5V is
missing
check
Fuse F1.
(F)
If Fuse
F1 is
open, check Diodes D1 and
D2
for
shorts.
(G) If
Diodes
D1 and D2 good, check
Regulator IC
(Q1)
for
a short.
(H)
Replace
Fuse F1 and
check for 10.5V
at
pin 1 of
Regulator
IC
(Q1).
PRINTER
CARRIAGE
ASSEMBLY
DOES NOT MOVE
(A) Turn Printer
OFF, move
carriage assembly
to
the
right.
Turn
Printer
ON. Carriage assembly
should
move
to Home position.
(B) If carriage
assembly
does not move, check
for
26V at pins
5 and
6
of
Connector CN4.
(C) If 26V is
missing, check
the power supply.
(D) If the
26V is present,
check for
7.37MHz at pins
18 and
19 of the CPU
IC
(Q8).
(E) If frequency
is not
correct, check
Crystal (OSC1)
by
substitution.
(F) Check
resistances
of Carriage
Motor winding
<M2).
(G) Check
CPU
IC
(Q8)
by
substitution.
(H) Check
the
Main Control Board
by substitution.
®
©
©
PRINT
HEAD WILL
NOT PRINT
(A) Check
the print
head
cable
Connector
CN3 for
good connection.
(B) Check for
26V at anode
and
cathode
of
Diode
D26.
(C)
Check
resistances of
print head.
(D)
Check CPU
IC
(Q8)
by substitution.
(E) Check
Main Control
Board
by substitution.
MISSING
DOTS
IN THE PRINT
PATTERN
(A)
Clean
print head
face.
(B) Check
print
head Connector
CN3
for
good con-
nection.
(C) Check
the flat
cable for broken
or pinched
lead.
(D) Disconnect
print
head
cable and
check re-
sistances
of the print
head.
(E)
Check
the print head
by substitution.
(F)
Check
Main Control
Board
by substitution.
LINE FEED
WILL NOT
OPERATE
(A) Check
Connector
CN5 for
good connection.
(B)
Check
resistances of
Line Feed
Motor
(M3).
(C) If the
resistances of
Line Feed
Motor are
good,
check
for 26V
at pins 5 and
6 of Connector
CN5.
(D)
Check Main
Control Board
by
substitution.
(E) If Line Feed
Motor is erratic
or
stops, check
the
gear assembly
on the left
hand
side for broken
gears.
PRINTER
WILL NOT
PRINT BY
COMPUTER
COMMAND
(A) Check
Connector
CN6 or
CN7 whichever
is
used
for
good connection.
(B) Check
the
cable between
the
Computer
and the
Printer
by
substitution.
(C) Check
Main
Control Board
by substitution.
Ill
PRELIMINARY
SERVICE CHECKS
(Continued)
CNS
CN10
CN7
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PLATEN
RIBBON
PROTECTOR
SNAP LEVER
PRINT HEAD
CARRIA6E
TOP
SHAFT
CNS-3
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SWITCH
POWER
TRANSFORMER
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CARRIA6E
ASSEMBLY
(3A) (4B) (4C)
PLATEN
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PRINT HEAD
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ADJUSTMENT
t-
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5
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N3
INTERCONNECTING DIAGRAM
IV
INTERCONNECTING
DIAGRAM
PRELIMINARY
SERVICE CHECKS
(Continued)
DISASSEMBLY
INSTRUCTIONS
UPPER COVER REMOVAL
Remove platen
knob, remove
top cover by pulling upwards.
Loosen two screws
holding switch assembly and slide
switch assembly
backwards. Remove two screws from in-
side
the front
of upper cover. Tip
upper cover back and lift
upper cover
from Printer.
PRINT HEAD
REMOVAL
Remove
upper cover, slide carriage
assembly to right end of
Printer. Carefully
remove print head cable plug from flat
cable connector
located on the carriage
assembly frame
beneath the print
head. Push down print head lock lever
and lift head
straight
up
from the carriage assembly frame.
PRINTER MECHANISM
REMOVAL
Remove Printer
upper cover. Slide
carriage assembly to far
right. Disconnect
print head cable plug and remove
print
head.
Remove the flat
cable connector screw and the con-
nector from
carriage frame
assembly. Cut plastic tie-wraps
that fasten flat
cable to side of printer mechanism.
Dis-
connect all
connectors
attached to
P.C.
board. Remove
P.C. board.
Set
Printer
up
side down on
a
soft cloth
and
remove four
screws holding mechanism
to the bottom of
cabinet.
Carefully remove
bottom case and set printer
mechanism upright.
MAIN CONTROL
BOARD REMOVAL
Remove upper
cover assembly.
Disconnect
all
connectors
from Main Control Board.
Remove print head assembly.
Remove flat cable connector from
carriage frame assembly.
Cut
the tie-wrap which fastens
the flat cable to the
right
side of printer
mechanism. Remove two screws
holding
Main Control
Board. Lift Main Control
from Printer.
PLATEN REMOVAL
Remove cabinet top
cover. Lift scale bar to highest
posi-
tion. Remove two screws holding paper
separator and
remove paper
separator. Remove C ring and platen
bearing
from
right
end
of platen. Pull left bearing side ways
from
side plate. Turn platen bearing
90°
and pull out platen.
CARRIAGE
MOTOR REMOVAL
Remove the upper
cover. Remove the Main Control
Board,
disconnect
Connector CN4. Cut
the tie wraps securing the
Carriage Motor leads.
Remove two
screws
fastening
the
Carriage Motor
to
the bottom
cover. Remove carriage belt
from Carriage
Motor pulley.
Lift Carriage Motor from
Printer.
PAPER FEED
MOTOR
REMOVAL
Remove upper case.
Remove Main Control Board. Remove
two phillips screws
fastening Paper Feed Motor to
left side
of printer
mechanism.
Remove Paper Feed
Motor
from
Printer.
VI
.IMINARY
SERVICE
CHECKS
(Continued)
PREVENTATIVE
MAINTENANCE
ENVIRONMENT
Computers
perform
best in
a clean,
cool
area
that
is below
80 degrees
Fahrenheit
and free
of
dust and smoke
particles.
Even
though
home
Computers
are
not
affected
by
cigarette
smoke
as much
as commercial
Computers
are
affected,
it is
better
to
maintain
a
smoke-free
area
around
the
Computer.
Do not
block
cabinet
vents
of
any
of the
Computer
system;
Computer,
Monitor, Printer,
or
other
power
devices.
ELECTRICAL POWER
Variations in the
line voltage
can
affect
the
Computer.
Try
to avoid
these
fluctuations
by using
an AC
receptacle that
is on
a power line
not
used
by appliances
or other
heavy
current
demand
devices.
A
power-surge
protector,
power-line
conditioner,
or
non-interruptable
power
supply
may
be needed to
cure the
problem.
Do
not
switch
power
On
and Off
frequently.
KEYBOARD
Liquids
spilled into
the
Keyboard can
ruin
it.
Immediately
after
a spill
occurs,
disconnect the
Computer
power plug
from AC
power
outlet.
Then,
if circuitry
or
contacts
are
contaminated,
disassemble
the Keyboard
and
carefully
rinse
the
Keyboard
printed
circuit
board with
distilled
water
and let
it dry.
Use a cotton
swab to
clean
between the
keys.
Use a
non-abrasive
contact
cleaner
and
lint-free
wipers on
accessible
connectors
and
contacts.
DISK
DRIVES
Clean the
read/write
heads
of
the
Disk
Drives
about
once
a month or
after
100
hours
usage.
Use only
an
approved
head
cleaning
kit.
Handle
carefully
to
preserve
proper
disk
head
alignment.
A
sudden
bump or
jolt
to the Disk
Drives
can
knock the
disk
head
out of
alignment.
If the
disk
drive must
be transported,
place
an
old disk
in slot
and close
door
during
transport.
Store
disks in
their
protective
covers
and
never
touch
the disk
surface.
Observe
the disk
handling
precautions
usually
found on
the
back of disk
protective
covers.
PRINTERS
Carefully
vacuum
the
Printer
regularly.
Wipe
surface areas
clean
using
a light
all-purpose
cleaner.
Do
not
oil
the
machine.
The oil
will
collect
abrasive
grit and
dust.
The
dust will
act as
a blanket.
This
can
cause
components
to overheat
and
fail.
STATIC
ELECTRICITY
Static
electricity
discharge
can affect
the
Computer. In
order to
minimize
the
possibility,
use
anti-static
mats,
sprays,
tools and
materials,
and maintain
good humidity
in
the
Computer
en-
vironment.
MONITOR
Use an
isolation
transformer
with any
Monitor
that
does not
come
as part of
the
system since
some
Monitors
use
a
HOT
chassis
(chassis
connected
to one
side of
the AC line).
The
face of
the Monitor
should never
be left
on for long
periods
of
time
at
high
brightness
level except
when
pattern
is
being
changed
periodically.
Use caution
when
cleaning
anti-glare
screens, to
preserve
the
glare-reduction
feature.
VII
PRELIMINARY
SERVICE
CHECKS
(Continued)
CHASSIS-TOP
VIEW
VIII
ATARI
MODEL
1025
$fiM
S
COMPUTERFACTS
ATARI
MODEL
1025
_
o
S
CM
CL
O
PRELIMINARY
SERVICE
CHECKS
ENCLOSED
INDEX
SAFETY
PRECAUTIONS
See page 29.
Page
Block
Diagram
17
Disassembly
Instructions
14
IC Pinouts
and
Terminal
Guides
16
Line
Definitions
15
Logic
Chart
13
Miscellaneous
Adjustments
14
Parts List
7,8,9
Photos
Chassis-Top
View
4
Page
Photos
(Continued)
Main Board
5,6,11,12
Safety Precautions
13
Schematics
2,3
Schematic Notes
13
Test Equipment
10
Troubleshooting
10
o
D
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->
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to
en
SAMS.
Howard
W. Sams
& Co.
4300 West 62nd Street,
P.O.
Box 7092, Indianapolis,
Indiana
46206 U.S.A.
The fisting
of any available
replacement part herein
does
not
constitute
in any
case a recommendation,
warranty or guaranty
by
Howard W.
Sams
& Co. as to the quality and suitability
of such
replacement
part.
The numbers of these parts
have been compiled
from
information
furnished to Howard
W. Sams
& Co. by
the
manufacturers
of the
particular type of replacement
part listed.
Reproduction
or
use,
without
express permission,
of editorial
or pictorial
content,
in any
manner, is prohibited.
No patent liability
is assumed with
respect to the
use of the information
contained herein.
£
1986
Howard
W. Sams & Co.
4300
West
62nd Street, P.O.
Box 7092. Indianapolis,
Indiana
46206 U.S.A.
Printed
in
U.S.
of
America.
86CP
14977
DATE
8-86
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8
PARTS LIST
AND DESCRIPTION (Continued)
When ordering
parts,
state Model, Part Number,
and Description
ELECTROLYTIC
CAPACITORS
ITEM
No.
RATING
MFGR.
PART No.
C3,C4
C11,
CI 2
2.2UF 35V
luF
35V
ITEM
No.
RATING
MFGR.
PART
No.
CI 3
C15
2.2uF 35V
1 uF 35V
CAPACITORS
ITEM
No.
RATING
MFGR.
PART
No.
C22
.1
250VAC
RESIS1rORS (Power
and
Special)
ITEM
No.
RATING
REPLACEMENT DATA
MFGR.
PART
No.
NTE
PART No.
WORKMAN
PART No.
RM1,RM2
RM3
RM4
RM5
RM6
Resistor
Network
(1)
Resistor Network
(2)
Resistor
Network
(3)
Resistor
Network (4)
Resistor
Network (3)
IHR-4-102 (5)
IHR-8-102JA
(5)
IHR-8-512JA
(5)
IHR-6-512
(5)
IHR-8-512JA
(5)
(1)
Contains
four
(4 ea.)
1000
ohms.
(2) Contains
eight
(8 ea.) 1000 ohms,
5%.
(3) Contains eight
(8 ea.) 5100 ohms,
5%.
(4)
Contains six
(6 ea.) 5100 ohms.
(5) On unit
number.
FUSE
DEVICES
§5
r-
>
o
in
ITEM
NO.
DESCRIPTION
MFGR.
PART NO.
NOTES
DEVICE
HOLDER
F1.F2 1.75A @
250V
Fast-
Acting
COILS
&
TRANSFORMERS
ITEM
No.
FUNCTION
MFGR.
PART No.
OTHER
IDENTIFICATION
NOTES
T1
Power
Transformer
4LP-45191-137
MISCELLANEOUS
ITEM
No.
PART
NAME
MFGR.
PART
No.
NOTES
LI 7
Ferrlte Bead
LED
1
LED
Power,
Red
Ml
Print
Head
M2
Carriage
Motor
M3
Line Feed Motor
M4
Home Position
Sensor
0SC 1
Crysta
1
7.37MHz
SK
Network
SW1
Switch
Power
SW2
Switch
Print
SW3
Switch
Paper End Detector
TEST EQUIPMENT
Test
Equipment listed
by
Manufacturer
illustrates typical or equivalent
equipment
used by SAMS' Engineers
to
obtain
measurements
and is compatible with most types
used by
field service
technicians.
TEST EQUIPMENT (COMPUTERFACTS)
Equipment Name
B & K Precision
Equipment No.
Sencore
Equipment No.
OSCILLOSCOPE 1570A,1590A,1596
SC61
LOGIC
PROBE
DP51
LOGIC PULSER
DP101
DIGITAL VOM 2830 DVM37,DVM56,SC61
ANALOG
VOM 277
ISOLATION TRANSFORMER TR1
10,1604,1653,1655 PR57
FREQUENCY COUNTER
1803,1805 FC71.SC61
COLOR BAR GENERATOR 121 1A,1248,1251,
1260 CG25.VA62
RGB GENERATOR 1260
FUNCTION GENERATOR 3020
HI-VOLTAGE PROBE
VOM/DMM
Accessory probes
HV-44
HP200
TEMPERATURE PROBE TP-28
CRT ANALYZER
467,470 CR70
TROUBLESHOOTING
POWER SUPPLY
If Printer is dead, check AC
Fuse (F2). If Fuse F2 is
open,
check Diodes D5
and D6 for shorts. If Fuse
F2 is good,
check for 31.5V AC between pins 3 and
4 and 9.8V AC be-
tween pins 1 and
2 of Connector CN1.
If voltages are not
correct, check Power
Transformer (T1), Power Switch (SW1)
and AC Line Choke (RC).
Check for 26V at cathode
of Diode D13. If voltage is not
cor-
rect, check SCRs D7
and D10 and associated
components.
Check for 10.5V at cathode
of Diode D4. If voltage is
miss-
ing check Fuse
F1. If Fuse F1 is open, check
Bridge Recti-
fiers (D1 thru D4), Voltage
Regulator IC
(Q1)
and
associated
components.
LINE FEED
MALFUNCTION
Turn platen knob by hand, if
platen
does
not turn smoothly,
check the
gear assembly on the left
side of the Printer. If
platen turns
smoothly, check resistance
of Line Feed Motor
(M3). Check for about 73
ohms between pins 1 and
5,
pins
3
and
5,
pins 2 and 6
and between pins
4
and 6
of Connector
CN5. If Printer will not
print while in self test mode,
check
waveforms
at pins
25 thru
28,
and 33 thru
36 of Interface
IC
(Q5).
If waveforms
are missing, check
IC Q5 and
CPU IC
(Q8)
by substitution. If waveforms are
present, check
ICs
Q3 and Q4 and Driver ICs TR1A and TR2A.
CARRIAGE ASSEMBLY DOES NOT MOVE
Check the
resistance
of the Carriage Motor
(M2),
check for
60 ohms between pins
5
and
1,
pins
5 and
3,
pins
6 and
2,
and pins6and
4 of Connector CN4. If resistances
are not
correct replace Carriage Motor.
If the carriage assembly moves erratically check
Home
Position
Sensor (M4). Check
Connector
CN10 for
good con-
nection. Check Interface IC
(Q5)
by substitution.
Check
IC
Q4.
MISSING DOTS IN PRINT
PATTERN
Actuate self
test mode.
Check for 26V P-P signal
at pins
8
thru 14 of Connector CN3.
If signal is present
on all
pins,
check
resistance
of Print Head (M1). If 26V
P-P signal is
missing at any pin check
CPU IC
(Q8)
by substitution.
If
signal
is low about 5V P-P check
Driver
ICs (IRA3 and IRA4).
10
C13
C2
R3
D51 C3
P
D50
D20
D18
D17
D15
D26 D22
D24 052 D54
031
033 C7 C10
C8
RM3
RM1
RM2
R32
R33
R20
RM5
C13
C14
O
3*
r-
>
o
012
R6
R7
R8
C17
R29
C6
D29
R30 R9
D43
C5
D45
D44
R15
R14 R13
R12
R11
R10
R19 R17
R18
C11
C21
C12
R21
C15
n
5.0V
D5
D6
BCE
F1
8
C
E
D27
TR12
TR11
TRA2
030
CN5
B C
TR2
L17
D55
034 CN6
B
C
TR3
B C
E
TR4
lit I
ill
BCE
CN7
E
C
B
TR5
TR6
TR1
E
C B
CN9
TR8
26.0V
NOTE:
ARROWS ON IC'S
INDICATE PIN
1
UNLESS
NOTED
A
Howard
W. Som«
tflUtt!IMMaJ
Photo
12
LOGIC
CHART
PIN IC IC IC
PIN IC PIN
IC PIN IC
PIN
IC
NO.
02 03 04
NO.
05
NO.
05
NO.
Q8
NO.
08
1 H
H
P
1
L 21 L 1
P 21
H
2
L L L
2
H 22
H 2 P 22 H
3 H P
P 3
L 23
H
3
P 23
H
4 L L
L
4
L 24
H 4 P
24 H
5
H
P
P
5
H
25
P
5
P
25
L
6
L L L
6
L 26
P
6
P
26 L
7
L L
L 7
H
27
P
7
P
27
H
8
L L
L 8
P 28
P
8
H
28
P
9
P
P
P
9
P
29
H
9
L 29 H
10 L
L L
10
P
30
H 10 L 30
P
11
P
P
P 11
P
31
H
11
H 31 H
12
L
L L
12
P 32
H
12
H
32 P
13
P
P
P 13
P
33
P
13 L 33 P
14
H H H
14 P 34
P
14
L
34 P
15
P
35
H
15
H
35 P
16 P 36 P 16
P
36
P
17
17 P
37
L 17 P 37 P
18
18
P
38 H 18 P 38
P
19
19
P 39 H 19 P 39 P
20
20
L
40
H 20
L
40
H
SAFETY PRECAUTIONS
1.
Use
an isolation
transformer for servicing.
2. Maintain
AC
line
voltage at rated input.
3. Remove
AC power from the Printer before servicing or installing
electrostatically
sensitive devices.
Examples
of typical
ES devices
are integrated circuits and semiconductors "chip"
components.
4. Use extreme
caution when handling the printed circuit boards.
Some
semiconductor devices can
be damaged easily
by
static electricity.
Drain off any
electrostatic
charge on
your body
by touching a
known
earth ground.
Wear
a
commercial-
ly available discharging
wrist strap device. This
should be removed prior
to
applying
power to the unit
under
test.
5. Use
a
grounded-tip,
low voltage soldering iron.
6. Use an isolation
(times
10)
probe
on scope.
7. Do not remove
or install board, mechanical or electrical
parts, or other peripherals with
Printer AC power On.
8.
Do not use freon-propelled
sprays. These can generate
electrical charges sufficient
to damage semiconductor
devices.
9.
This Printer
is equipped
with
a
grounded three-pronged AC plug. This
plug must fit into
a
grounded
AC power
outlet. Do
not
defeat the AC plug
safety feature.
10. Periodically
examine the
AC power cord for damaged or cracked
insulation.
11. The Printer
cabinet is
equipped with vents to prevent heat
build-up. Never block, cover, or obstruct
these vents.
12. Instructions
should
be
given,
especially to children, that
objects should not be dropped or pushed into
the vents of the
cabinet.
This
could cause shock or equipment
damage.
13. Never expose
the Printer
to water. If exposed to water
turn the unit Off. Do not
place
the Printer
near possible
water
sources.
SCHEMATIC NOTES
o
ro
_a_
Circuitry not used
in some
versions
Circuitry used
in some
versions
e
See
parts list
+
Ground
Voltages
measured
with digital
meter.
Waveforms
and voltages are
taken
from ground,
unless
noted otherwise.
Voltages,
waveforms and
logic readings
taken with
Printer
running in Self-Test
mode.
Waveforms
taken with
triggered scope
and
Sweep/Time
switch
in Calibrate
position,
scope
input set
for DC
coupling
on
"0"
reference
voltage
waveforms.
Switch to
AC input to
view waveforms
after DC
reference
is
measured when necessary.
Each
waveform
is 7.5cm
width with
DC
reference voltage
given at the
bottom
line
of each waveform.
Item
numbers in rectangles appear in
the alignment/ad-
justment
instructions.
Supply
voltage
maintained as
shown at
input.
Controls
adjusted
for
normal
operation.
Terminal
identification
may
not be
found
on unit.
Capacitors
are 50
volts or
less, 5%
unless
noted.
Electrolytic
capacitors
are 50
volts
or less, 20%
unless
noted.
Resistors
are
V2W
or less,
5%
unless noted.
Value
in
(
)
used
in
some
versions.
Measurements
taken
with
switching as
shown,
unless
noted.
13
DISASSEMBLY INSTRUCTIONS
UPPER COVER REMOVAL
MAIN CONTROL BOARD REMOVAL
Remove platen knob, remove
top
cover
by
pulling
upwards.
Loosen two screws holding
switch assembly and slide
switch
assembly backwards. Remove two screws from
in-
side
the front of
upper cover. Tip upper cover back
and lift
upper cover
from Printer.
PRINT
HEAD
REMOVAL
Remove upper
cover, slide carriage
assembly to right end
of
Printer. Carefully
remove print
head cable plug from flat
cable connector
located on the
carriage assembly
frame
beneath the print head.
Push
down print head lock
lever
and
lift
head straight
up
from
the carriage assembly
frame.
PRINTER
MECHANISM
REMOVAL
Remove
Printer
upper cover. Slide
carriage assembly
to
far
right.
Disconnect print
head cable plug
and remove print
head. Remove
the flat
cable connector screw and the
con-
nector from
carriage frame
assembly. Cut plastic lie-wraps
that fasten flat
cable to side of printer
mechanism.
Dis-
connect
all connectors
attached to P.C. board.
Remove
P.C.
board.
Set Printer
up
side
down on a soft cloth
and
remove
four screws
holding mechanism
to the bottom of
cabinet. Carefully
remove bottom
case
and
set printer
mechanism
upright.
Remove upper cover assembly. Disconnect
all
connectors
from Main Control Board. Remove print
head
assembly.
Remove flat cable connector from carriage
frame
assembly.
Cut
the
tie-wrap
which fastens the
flat
cable to the right
side
of printer mechanism. Remove
two
screws holding
Main Control Board.
Lift
Main Control from
Printer.
PLATEN
REMOVAL
Remove
cabinet
top
cover. Lift
scale bar to highest
posi-
tion.
Remove two screws holding
paper separator
and
remove paper
separator. Remove
C ring and platen
bearing
from right end of
platen.
Pull left bearing side
ways from
side plate. Turn platen bearing
90°
and pull
out platen.
CARRIAGE MOTOR REMOVAL
Remove the upper cover. Remove the Main
Control Board,
disconnect
Connector
CN4. Cut the tie wraps securing
the
Carriage Motor leads. Remove two screws fastening
the
Carriage
Motor
to
the bottom cover.
Remove carriage belt
from Carriage Motor pulley. Lift Carriage
Motor
from
Printer.
PAPER FEED MOTOR
REMOVAL
Remove
upper case.
Remove Main Control Board.
Remove
two phillips screws fastening Paper Feed Motor
to left side
of
printer mechanism. Remove Paper
Feed Motor from
Printer.
MISCELLANEOUS
ADJUSTMENTS
FIRST
CHARACTER PRINTING
POSITION ADJUSTMENT
PLATEN/PAPER
SEPARATOR
ADJUSTMENT
Loosen screws
fastening Carriage Motor to bottom
cover.
Turn motor
assembly
a
little one way
or the other
so
that
when
the
power is turned ON, the
print head returns and
stops
at the home sensor
position within tolerance, see
Figure 1. If changing position of motor
assembly does not
correct the print position, change the
engagement position
of the
carriage synchro-belt
on
the pulley by one or two
teeth.
CN10>-
1mm
-0.55-0.75mm
Home
TjL-LI
ri
—I Sensor
DETECTOR
'U
LEVER
a
Figure
1
Remove the
upper
cover,
loosen the
paper separator
screws. Adjust
the
clearance
between
the platen and the
paper separator
for
approximately
0.5mm.
Tighten the
paper separator
screws,
see
Figure
2.
PAPER
SEPARATOR
\
0APPROX
Figure 2
/
PRINTHEAD ADJUSTMENT
Print head adjustment
should be
performed after repair of
printer mechanism, carriage assembly
frame, or print head.
Loosen carriage shaft screws on the
sides of the printer
mechanism. Move carriage shaft
forward or backward until
gap between
platen and print head is between 0.45mm
and
0.5mm.
14
LINE DEFINITIONS
ADO
THRU AD7 Address Bus, BitsOThru7
COMMAND
Input
to
Counter
DATA IN
Serial Port's Receiver
Data Input
DATA
OUT Serial Port's Transmitted Data
P1.0THRUP1.6
Port 1 Bit Thru Port 1 Bit
6
5V READY
Interrupt, Vectored
to
Service Program
15
IC PINOUTS &
TERMINAL
GUIDES
1DENT
iDEtrr
12
3 4 5
RM1.RM2
FRONT VIEW
D81S5C
^r~
PC3 VCC
PC4 PCS
TIHER
IN
PCI
RESET
PCO
PCS P97
PBS
TIMER OUT
lO/H
PBS
CE P64
fiti PBS
1r
PB2
ALE
PB1
AOO
PBO
Ml PA7
AD2
PAS
ADS PAS
AIM PA4
A05 PAS
A06 PAS
AD7 PA1
6ND
PAO
+
rnnrnnnr
1
2 3 4 S 6 7 6
RM3,RM4,RM6
FRONT
VIEW
1DENT
05
SRAM
TOP VIEW
IC
314
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313
1L
3C 312
I4C
311
310SL.
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6C 3
S
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02,03,04
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