OKIDATA OKIMATE 20, EN3211 Service Manual
HOWARD
W.
SAMS
&
COMPANY
CP34 09015
COMPUTERFACTS™
Technical
Service Data
OKIDATA®
OKIMATE
20
(MODEL
EN3211)
PRINTER
FEATURES
COMPLETE
SCHEMATICS •
PRELIMINARY
SERVICE CHECKS
•
TROUBLESHOOTING
TIPS
EASY-READ
WAVEFORMS
• REPLACEMENT
PARTS LISTS •
SEMICONDUCTOR
CROSS-REFERENCE
SAM§
COMPUTERFACTS'
0K1DATA
MODEL
EN3211
OKIMATE 20
PRELIMINARY
SERVICE
CHECKS
This data provides
the user
with a
time-saving
service tool
which is designed
for
quick
isola-
tion
and repair
of
Computer system
malfunc-
tions.
e.'i
m
I-
o
<
,_
Q
T-
O
Z
m
pri
O
o
CO
Ql
O
Check all
interconnecting
cables
for good
connection
and
correct hook-up
before
making
service
checks.
Always
turn
Printer
Off before
connecting
or
disconnecting
connectors,
boards
or Computer.
Replacement
or
repair of
the Power
Supply,
Driver
Board,
Interface
Board
or
connectors
may be
necessary
after the
malfunction
has
been
isolated.
TEST
EQUIPMENT
Digital
Volt/Ohm
Meter
Resistor,
390
Ohms,
1/2W
Resistor,
30
Ohms,
10W
TOOLS
Head
Cleaning
Equipment
(Ethyl
Alcohol)
Contact
and
Switch
Cleaner
(non-spray
type)
Phillips
Screwdriver
Flat-Blade
Screwdriver
IC Insertion
and
Removal
Tools
28
pin
Low
Wattage
Soldering
Iron
Desoldering
Equipment
REPLACEMENT
PARTS
AND
DESCRIPTION
F
Fuse
2
Q1
Transistor
(Power
Supply
Board)
S i
Br
i
dge
Rect
i
f i er
SW
0n~0ff
Switch
LI
Coil
R1
Resistor,
5.1
Ohms
3W
M7
Print
Head
01
ROM
IC
Ml
Line
Feed
Motor
M5
Home
Position
Sensor
M2
Carriage
Motor
SW3
Ribbon
End
Switch
M4
Paper
End
Sensor
SAMS
Howard
W.
Sams
& Co.
4300
West
62nd
Slreef,
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
!isted
-
87CP19021
DATE
11-8?
Reproduction
or use,
without express
permission,
of
editorial or pic-
torial
content,
in any
manner, is
prohibited.
No
patent liability
is
assumed
with
respect
to the
use of the information
contained herein.
©
1987
Howard
W. Sams
& Co.
4300 West
62nd Street,
P.O.
Box
7092, Indianapolis,
Indiana
46206
U.S.A.
Printed in
U.S. of America
PRELIMINARY
SERVICE CHECKS (Continued)
DISASSEMBLY
INSTRUCTIONS
CABINET
REMOVAL
Remove
ribbon cartridge
and carriage
assembly
cover.
Remove two screws located In front of
Carriage
assembly holding cabinet top to
chassis.
Push
cabinet
top
toward rear to re-
lease
tabs
on Inside rear edge and lift up
r&ar.
When
rear edge is clear of chassis,
move
top
forward to
clear
front tabs and lift
top
from
Printer.
PRINTER
MECHANISM REMOVAL
Remove
Control
Panel
Connectors
CN4 thru CN8.
cover
Dl sconnect
NOTE:
Lift up
cap on Connector
CN6
before
pulling
flat ribbon cable
out.
Remove three
screws
holding mechanism to
cabinet bottom.
POWER
SUPPLY
AND DRIVER
BOARD REMOVAL
Remove cabinet top
and Printer mechanism.
Remove
two screws holding Power
Supply
Board
to
cabinet bottom.
Push
back
tabs
holding
front of Driver
Board and lift
Driver
and
Power Supply
Boards from cabinet.
CARRIAGE
MOTOR ASSEMBLY REMOVAL
Remove
cabinet top. Disconnect
Connector
CN6
from
Driver
Board.
Remove two screws holding
motor
assembly
and remove
assembly.
PAPER FEED
MOTOR REMOVAL
Remove
Printer
mechanism.
Disconnect Connec-
tor
CN8
from
Driver
Board. Remove two
screws
holding Paper
Feed Motor and
remove Motor.
BELT
REMOVAL
Remove
cabinet top
and Control Pane!
cover.
Remove
Carriage Motor
assembly.
Remove
two
springs from
metal linkage
going
from Head
Hold
Solenoid to left
belt gear
(one spring
at
each
end
of
the link).
Insert a
flat-blade
screwdriver between left
belt
gear and
metal
link. Pry link
and ribbon stop
lever
off gear
post,
note position of
ribbon stop
lever
for
reassembly. Remove
belt from
Print Head
assem-
bly and
gear
pul
leys.
RIBBON REMOVAL
Turn
Power Off.
Lift ribbon
access cover.
Pull back on Print
Head assembly
until It
snaps back.
Lift used
ribbon
cartridge out.
Place
new
cartridge Into
compartment,
rear end
first.
While lowering
front end, make
sure
ribbon Is In
front
of
Print Head
and
behind
ribbon guides.
Snap head back
into
printing
pos 1 1 1 on
REPLACING PRINT
HEAD
Remove
ribbon cartridge. Pull
back on
Print
Head Lock Lever,
directly behind
Print Head.
Lift
Print Head straight up
out of holder.
m
(5D
17
CN3
M7
CN6
M4
(7C)
Jb)@
®
@®
^
©@
GEAR
ASSEMBLY
6A)
CHASSIS-OVERALL VIEV
SERVICE
CHECKS
MATCH
THE
NUMBERS
ON
THE
INTERCONNECTING
DIAGRAM
AND PHOTOS
WITH
THE
NUMBERS
ON THE
SERVICE
CHECKS
TO
BE
PERFORMED.
PRINTER DEAD
(A) Check Fuse F on
Power Supply
Board.
If open, check
for possible shorts
at Diode
S 1 1
and
Oscillator Transis-
tor
(Ql)«
(B)
If Fuse F
is good, apply power and
check for
167V
at the cathode of
Diode Sit.
if
167V
is missing,
check On-Off Switch
(SW), Coil
LI,
Resistor
R1
and
Diode
Sil.
(C) If
!67V
is present at
Diode Sil,
check for
14.4V
at pin
1 of Connec-
tor
CN9 on Driver Board.
If
reading
is not correct,
check adjustment of
Voltage Adjust
Control CVR).
(D) If
14.4V is missing at pin 1 of Con-
nector
CN9, turn Power
Off, discon-
nect Connector
CN9 and connect a
390
Ohms resistor from
pin 3 to pin
4
and
a
30
Ohms 10W
ioad from pin 1 to
pin
6 of Connector
CN on
Power
Sup-
ply. Apply power and
recheck Power
Supply output voltages.
if voltages
are
still missing,
troubleshoot
Power
Supply Board.
If voltages
re-
turn, troubleshoot
Driver and Inter-
face
Boards.
(C)
Check
ROM IC
(Q1
) by substitution.
(D
PRINT HEAD WILL
NOT PRINT
(A) Check
Print
Head
(M7)
connections
and Connector
CN6. Check Print Head
Ribbon Cable.
(B)
Examine element points
on Print
Head.
If
elements appear
dirty,
clean
Head with a soft cloth
dampen-
ed with
ethyl alcohol.
If elements
appear
white,
substitute Print Head.
(5)
MISSING DOTS
IN THE PRINT PATTERN
(A) Clean Print Head
face with a soft
cloth
dampened
with ethyl alcohol.
CB)
Check Print Head connections
Connectors
CN3
and
CN6.
and
(T)
PRINTER WILL
NOT PRINT BY
COMPUTER COMMAND
(A)
Check Connector
CN2 on Interface
Board.
(B) Check settings
of DIP Switches
SW1
and
SW2 on Interface Board.
See
"Switch Settings"
for
a list of the
various settings.
(?)
PRINTER
CARRIAGE
ASSEMBLY
Q
(A)
Carriage
asembly
does
not
move.
Check
carriage
assembly belt, gears
and
pu I leys.
(B)
Check
Connectors
CN3, CN5, CN7 and
CN9.
(C) Check
Carriage
Motor
(M2)
windings
for
continuity.
Check
for 14 Ohms
from
pin
1 to
pin
5,
pin
3
to pin
5,
pin
2 to
pin 6 and
pin 4 to pin 6 of
Connector
CN7.
(D)
Carriage
assembly
moves to right
only
and
stops.
Check operation
of
Home
Position
Sensor.
Check for
4.5V
at
pin
8 of Connector
CN5
when
Print
Head
is at
Home Position and
0V when
Head
is not at
Home Postion.
If readings
are not
correct, check
pins
6,
7 and
8 of Connector
CN5
and
the Home
Position
Sensor (M5).
LINE
FEED WILL
NOT
OPERATE
(A) Check
Line
Feed
gear assembly on
right
side of
platen.
(B)
Check
Connector
CN8.
(C) Check
windings
of
Line Feed Motor
(Ml) for
continuity.
Check for
7
Ohms
from
pin
1 to pin
5,
pin 3 to
pin
5,
pin
2 to pin
6 and pin
4 to
pin
6 of Connector
CN8.
READY
LED
BLINKS
(A) Ready
LED
blinks,
pressing Select
Switch
has no
effect.
Check pins
1
thru
5 of
Connector
CN5.
(Bi
Turn Printer
Off. Check
operation
of
Ribbon
End
Switch
(SW3) with an
ohmmeter
at pins
1
and
2 of
Connector
CN5. The
reading
should be zero
ohms
with
Switch
activated and
infinity
with
Switch
not activated.
(C)
Turn Printer
On
and check
operation
of
the Paper
End
Sensor
(M4).
Check
for
5.0V
at
pin
1 of Connector
CN5
with
paper
in Printer
and
0V
with
no
paper.
NOTE:
The Ribbon
End Switch must
not be
activated.
If readings are not correct, check
Paper End
Sensor
(M4).
PRELIMINARY
SERVICE CHECKS (Continued)
POWER SUPPLY BOARD
@
Q1
@.
®
SW2
8W1
CN2
x
INTERFACE
BOARD
IV
PRELIMINARY SERVICE
CHECKS
(Continued)
:N.'f:«
''
,'•','.
'•;;
#
.-
^
'^'
;:
''^
;:
#§'Mi
II
I*
'
"
..
.
t
«.
.,
*
:
:
;
I
-
.
:
»
-
•;
•
m^mmBmu
7-
f
/
-
/-
//
CN3
CNS
CN5
CN5
v
—
^—
^
£7\
4.5V/0V
(SB)
/ \
0/1NFSNITY
\
/
: -
5
5V/0V
PIN
1
CN7
CN7
CN9
14.6V
©
D
m
ZO
w
t;
-L
>
^
>
m
DRIVER
BOARD
PRELIMINARY
SERVICE CHECKS
(Continued)
GENERAL
OPERATING
INSTRUCTIONS
SELF-TEST
Self-Test
continuously
prints
the
character
set. To start
test,
hold
Select
button
down
while turning
Printer
On.
Continue
to
hold
Select button
for
two
seconds,
then
release
it. To
stop test,
press
Select
button.
NOTE: Do not
use
a
colored
ning
Sel
f-Test.
ribbon
when
run-
DARKNESS
BUTTON
Slide
Darkness
button
to
left to
print
lighter,
to
right
to
print
darker.
SELECT
BUTTON
Press
Select
button
once
to
pause,
ready
LED
will
start
blinking.
To Form
Feed,
pause
Printer,
press
and
hold
Select
button
for
two
seconds.
SWITCH
SETTINGS
SWITCH SW1
300 Baud
1200
Baud
4800 Baud
9600 Baud
7 Bit with parity
8
Bit with
parity
8 Bit without parity
Even
parity
Odd
parity
X-0N/X-0FF Protocol
Ready
/Busy
Protocol
Space
at printer
ready
(Ready=High,
+)
Mark at printer
ready
(Ready=Low,
-)
ON
i
2
1,2
3,4
3
1 nterf ace Board
Switches
OFF
SWITCH SW2
ON
U2
Spanish
Characters 1
2 ASCI
I
Characters
1
17.1
CP1
(Characters
per inch) 2
10
CPI
Auto LF (linefeed)
On 3
4
Auto
LF Off
3,4
IBM
Character Set #1
IBM Character Set #2
4
5
Draft Quality
6
6
Correspondence Quality
OFF
:
2
3
<.
MISCELLANEOUS
ADJUSTMENTS
POWER
SUPPLY VOLTAGE
ADJUSTMENT
Connect
input of
a DC
voltmeter
to pin
1 of
Connector
CN9
on Driver
Board.
Adjust
Voltage
Adjust Control (VR>
for
14.4V.
PRINT HEAD
CLEARANCE
Remove
cabinet
top.
Loosen
Phillips
screw
holding
Head
Hold
Solenoid
to
Printer
chassis.
Move Solenoid
to
align
metal
slide-bar
index
marker
with index
marker
on
plastic
end
piece.
NOTE: Head Hold
Solenoid
while
making
this
adjustment.
is
not
activated
Clearance
between
ribbon
guide
and
platen and
between
ribbon
guide
and
ribbon
stop
rubber
should
be
.02 to
.04
inch (5
to 1mm).
Tighten
Solenoid
mounting
screw.
BELT
TENSION
Remove
cabinet
top.
Loosen
two screws
holding
Carriage
Motor.
Measure
tension
of belt
by
hooking
a
tension
guage
in
hole
located
on
left
front
of
the
Carriage
Motor.
Pull
guage
until
a tension
of .66
+
.066
pounds (300
+
30
grams)
is reached
and
tighten
Motor
mount
screws.
VE
PRELIMINARY
SERVICE CHECKS
(Continued)
ft*
§©
®
*-
sn en r\s a©
~
V VV V V V
ImAmj Mill
©
.K8
li
<
a.
t
i
_i
?
o
cc
1—
7-
o
o
g
si
sTTT
C£.
r-a"o
vHEIl-
J
**
®®
zi
5®
©
5*
01
UJ
o
fcl?
X®
^fe
@
(D
S:
©
;DD
(D
CD
r^Vn®
-
s<"
5®"
!1
ill®
is
o
m
z
o
-*
>
i
;»
O
I
g
©
Q
CC
<
o
CD
UJ
o
'<
u_
a:
UJ
|©
s|0000flB|
©
p
—
I
HOODOO
I
1
INTERCONNECTING
DIAGRAM
VP
PRELIMINARY
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 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.
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 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.
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 period 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.
VIII
SAM
S
COMPUTERFACTS"
OKIDATA
MODEL
EN3211 OKIMATE 20
o
CM
LU
I-
<
oz
UJ
_i
UJ
Q
O
CO
Q-
O
SAFETY
PRECAUTIONS
See Page 29
INDEX
Page
Block
Diagram 28
Disassembly Instructions
27
General Operating
Instructions.... 18
GridTrace Location Guide
I
nterf
ace
Board
22
Power Supply Board 20
IC
Pinouts and
Terminal Guides....
8
Line Definitions
11
Logic
Chart 17
Miscellaneous Adjustments
18
Parts List
12 thru
16
Page
Photos
Chassis-Overall View
24
Dr i ver Board
4,
25
I
nterf ace Board
22,23
Power
Supply
Board
20,21
Safety Precautions 29
Schemat i
cs
2
,
3
,5,
6,
7
,
26
Schematic Notes
19
Test Equipment 9
Troub
leshoot i ng
9,10,11
o
o
o
m
r-
m
z
O
to £
-1
>
OH
7s
>
m
to
o
SAMS.
Howard W.
Sams
& Co.
f
r«i
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
87CP19021 DATE
11-87
Reproduction or
use,
without express permission, of editorial or pic-
torial content, in
any manner, is
prohibited.
No patent liability is
assumed with
respect to the use
of the
information contained
herein.
©
1987 Howard
W.
Sams
&
Co.
4300 West 62nd Street, P.O. Box 7092, Indianapolis, Indiana 46206
U.S.A. Printed in U.S. of America
A
PHOTOFACT
STANDARD NOTATION
SCHEMATIC
withhehubhi
© Howard W. Sams &
Co.
1987
OKIDATA
MODEL EN3211
OKIMATE 20
S.OVCB)
A
PHOTOFACT
STANDARD NOTATION
SCHEMATIC
with
HEHffiEEBl
©
Howard W. Sams & Co.
1987
26
o
"D
CO
J*
s
o
D
m
m
O
3
>
H
m
N5
O
O
2
o
Loading...