OKIDATA OKIMATE 20 User 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 atime-saving
service tool which is designed for quick isola-
tion and repair of Computer system malfunc-
tions.
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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
FFuse 2
A
Q1 Transistor (Power Supply Board)
Si
1
Br idge Rect ifier
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 arecommendation, 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 aflat-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 111on
.
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.
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ASSEMBLY
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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 Fon Power Supply Board.
If open, check for possible shorts
at Diode S11and Oscillator Transis-
tor (Ql)«
(B) If Fuse Fis 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 1of 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 1of Con-
nector CN9, turn Power Off, discon-
nect Connector CN9 and connect a390
Ohms resistor from pin 3to pin 4
and a30 Ohms 10W ioad from pin 1to
pin 6of 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 asoft 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 asoft
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 alist of the
various settings.
(?) PRINTER CARRIAGE ASSEMBLY
Q
(A) Carriage asembly does not move.
Check carriage assembly belt, gears
and pu Ileys.
(B) Check Connectors CN3, CN5, CN7 and
CN9.
(C) Check Carriage Motor (M2) windings
for continuity. Check for 14 Ohms
from pin 1to pin 5, pin 3to pin 5,
pin 2to pin 6and pin 4to pin 6of
Connector CN7.
(D) Carriage assembly moves to right
only and stops. Check operation of
Home Position Sensor. Check for
4.5V at pin 8of 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, 7and 8of 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 1to pin 5, pin 3to
pin 5, pin 2to pin 6and pin 4to
pin 6of Connector CN8.
READY LED BLINKS
(A) Ready LED blinks, pressing Select
Switch has no effect. Check pins 1
thru 5of Connector CN5.
(Bi Turn Printer Off. Check operation
of Ribbon End Switch (SW3) with an
ohmmeter at pins 1and 2of 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 1of 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
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INTERFACE BOARD
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PRELIMINARY SERVICE CHECKS (Continued)
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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 acolored
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
7Bit with parity
8Bit with parity
8Bit 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
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1,2
3,4
3
1nterf ace Board Switches
OFF SWITCH SW2 ON
U2 Spanish Characters 1
2ASCI ICharacters
117.1 CP1 (Characters per inch) 2
10 CPI
Auto LF (linefeed) On 3
4Auto LF Off
3,4 IBM Character Set #1
IBM Character Set #2 4
5Draft Quality 6
6Correspondence Quality
OFF
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MISCELLANEOUS ADJUSTMENTS
POWER SUPPLY VOLTAGE ADJUSTMENT
Connect input of aDC voltmeter to pin 1of
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 atension guage in hole located on
left front of the Carriage Motor. Pull guage
until atension of .66 +.066 pounds (300 +30
grams) is reached and tighten Motor mount
screws.
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PRELIMINARY SERVICE CHECKS (Continued)
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PRELIMINARY SERVICE CHECKS (Continued)
PREVENTATIVE MAINTENANCE
ENVIRONMENT
Computers perform best in aclean, 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 asmoke-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 apower line not used by appliances or other heavy current demand
devices. Apower-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 aspill 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 acotton swab to clean between the keys. Use anon-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 amonth or after 100 hours usage.
Use only an approved head cleaning kit.
Handle carefully to preserve proper disk head alignment. Asudden 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 alight all-purpose
cleaner. Do not oil the machine. The oil will collect abrasive grit and dust. The dust will act as
ablanket. 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 aHOT 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

SAMSCOMPUTERFACTS" OKIDATA
MODEL EN3211 OKIMATE 20
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SAFETY PRECAUTIONS
See Page 29
INDEX
Page
Block Diagram 28
Disassembly Instructions 27
General Operating Instructions.... 18
GridTrace Location Guide
Interf 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 iver Board 4, 25
Interf ace Board 22,23
Power Supply Board 20,21
Safety Precautions 29
Schemat ics 2,3,5,6, 7,26
Schematic Notes 19
Test Equipment 9
Troub leshoot ing 9,10,11
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SAMS. Howard W. Sams &Co.
fr«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 arecommendation, 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

APHOTOFACT STANDARD NOTATION SCHEMATIC
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©Howard W. Sams &Co. 1987
OKIDATA
MODEL EN3211 OKIMATE 20

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©Howard W. Sams &Cc. 1987

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©Howard W. Sams &Co. 1987 ALTERNATE POWER SUPPLY

IC PINOUTS &TERMINAL GUIDES
D2712B
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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)
Ecjuipmerrt
B&KPrecision
Equipment No.
Sencore )
Equipment No. Notes
OSCILLOSCOPE 1570A,1590A,1596 SC61
LOGIC PROBE DP51.DP21
LOGIC PULSER DP101.DP31
DIGITAL VOM 2830,2806 DVM37,DVM56,SC61
ANALOG VOM 277,111,116
ISOLATION TRANSFORMER TR1 10,1604,1653,1655 PR57
FREQUENCY COUNTER 1803,1805 FC71.SC61
COLOR BAR GENERATOR 1211A.1251, 1260,1249 CG25.VA62
RGB GENERATOR 1260,1249
FUNCTION GENERATOR 3020,3011,3030
HI-VOLTAGE PROBE
VOM/DMM
Accessory probes
HV-44
PR-28(HV)
HP200
TEMPERATURE PROBE TP-28JP-30
CRT ANALYZER 467,470 CR70
DIGITAL IC TESTER 560,550,552
CAPACITANCE ANALYZER LC53,LC75,LC76
LC77
INDUCTANCE ANALYZER LC53,LC75,LC76
LC77
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POWER SUPPLY
NOTE: Use an
step down contro
TROUBLESHOOTING w
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isolation transformer with
when servicing power supply-
Disconnect Connector CN9 from
avoid possible damage to Pr
voltage that may be produced
Power Supply.
Dr iver Board to
nter from high
while servicing
NOTE: Power Supply will not operate properly
if Connector CN9 is disconnected from Driver
Board unless the proper bias and load Resis-
tors are connected to Connector CN9.
Connect a390 ohms 1/2W bias Resistor from pin
3to pin 4and 4700 ohms 1/2W bias Resistor
from pin 3to pin 5of Connector CN9. Also
connect a30 ohms, 10W load Resistor from pin
1to pin 6and a10 ohms, 10W load Resistor
from pin 5to pin 6of Connector CN9.
POWER SUPPLY DEAD
Check Fuse F. If fuse is open, check for
possible shorts at Bridge Rectifier S11and
Oscillator Transistor (01). If fuse is good,
apply AC power and check for 120V AC at the AC
input pins of SI1. If 120V AC is missing,
check Resistor R1 ,Coil LI and Switch SW. If
120V AC is present, check for 167V at the cath-
ode of SIT- If 167V is missing, check S11-
If 167V is present, check waveform at base of
Oscillator Transistor (01). If waveform is
missing, check voltages and components asso-
ciated with 01 and Regulator Transistor (Q2)
and check Transformer TR.
The 14.4V Source is missing
Diode SI2, Capacitor C11 and
on Transformer TR from pin 6
tinuity.
,Check Coi IL2,
check the winding
to pin 7for con-
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The 14.6V source is not correct and adjusting
voltage Adjust Control VR has no affect.
Check voltage and components associated with
Error Amp Transistor (03) and Optoisolator
(PC).
Regulated 5.0V source is not correct or miss-
ing. Check 5V Regulator IC (A), Diode SI3,
Capacitors CI 4and CI 5and check winding on
Transformer TR from pin 8to pin 9for continu-
ity.
The -9.0V source is missing at pin 7of
Connector CN9 on Driver Board. Check Diode
Si4, Capacitor C16 and Resistor R15 on Power
Supply Board and Zener Diode D1 and Capacitor
C6 on Interface Board.
The 9.0V source is missing on the Interface
Board (cathode of Zener Diode D2). Check
Zener Diode D2 and the voltages and components
associated with Regulator Transistor (TR1) and
Switch Transistor (TR3).on Interface Board.

TROUBLESHOOTING (Continued)
CPU OPERATION
Check for a11 .059MHz waveform at pin 19 of
CPU IC (Q6) on the Interface Board. If wave-
form Is missing or frequency not correct,
check Crystal X1 ,Capacitor C12 and IC Q6.
Check Reset logic at pin 9of IC Q6 while turn-
ing Printer On. The logic should be High then
immediately go Low and stay Low. If logic is
not correct, check Capacitors C1 1and C2,
Resistor P.] 2, IC Q6 and Module HIC.
PRINT HEAD
Print Head not printing or dots are missing
(Head Hold Solenoid works). Examine element
points on Print Head- If element points
appear dirty, clean Head with asoft cloth
dampened with ethyl alcohol. If element
points appear white, Print Head may be bad.
Substitute Print Head and check Printer oper-
ation. If Print Head is good, check Print
Head contacts, pins 1thru 10 of Connector CN6
on Driver Board and pins All, A12, B12 and
of Connector CN3 on Driver Board and CN1
Interface Board for good
connections are good, check
10 of Connector CN6. if
check Diode D20. If 14.2V
connections.
for 14.2V at
14.2V is missing,
is present, check
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Interface IC (Q3) on the Interface Boarc
PRINT HEAD HOLD SOLENOID DOES NOT WORK
Check Fuse F1 on the Driver Board. If Fuse is
open, check for apossible shorted Head Hold
Solenoid (M3), Diode D19 or Solenoid Switch
Transistor (TR3). If Fuse Is good, check Con-
nector CN4 and pin B11 of Connector CN3 for
good connections and check Solenoid M3 winding
for continuity (6.7 ohms). If Connectors and
Solenoid are good, run Printer in Self-Test
mode and check waveform at the base of Tran-
sistor TR3. if waveform Is missing, check
Interface IC (Q4) on the interface Board. If
waveform is present, check Transistor TR3 and
Diode D19.
CARRIAGE MOTOR
Carriage assembly moves to right and stops or
moves to left and bangs against left stop.
Check operation of Home Position Sensor (M5),
refer to the "Sensor" section of this Trouble-
shooting guide.
Carriage assembly does not move. Check belt,
pulleys and carriage mechanism for smooth oper-
ation with no binding. If no problem is
found, check Fuse F2 on Driver Board. If Fuse
is open, check Switch Transistors (TR1 and
TR2), Diode Di and Driver Transistor Array
(Q1) for possible shorts. If Fuse F2 is
turn Printer On and check for 14.4V at
of Connector CN9 on Driver Board. if 14.
missing, refer to the "Power Supply" section
of this Troubleshooting guide. If 14.4V is
present, check waveforms at pins B4, B8, B9,
B10, A6 and A9 of Connector CN3 on Driver
Board. If waveforms are missing, check inter-
face IC (Q3) on Interface Board.
are present, check waveform at
Module HIC on Driver Board. If
good,
pin i
.4V is
missing, check Module HIC.
Ifwaveforms
pin 13 of
waveform is
waveform Is
present, check Switch Transistor (TR2), Diodes
D6 thru D17 and Driver Transistor Array (Q1).
Check Carriage Motor (M2) windings for continu-
ity, and check Connector CN7 for good connec-
tions.
LINE FEED MOTOR
Line Feed Motor (Ml) does not work. Check
Fuse F2. If Fuse is open, check Switch Tran-
sistors (TR1 and TR2), Diode DI and Driver
Transistor Array (Q1 )for possible shorts. If
Fuse is good, check Connector CN3 for good con-
nections. If Connector is good, check for
14.4V at pin 1of Connector CN9 on Driver
Board. If 14.4V is missing, refer to the
"Power Supply" section of this Troubleshooting
guide. If J4.4V is present, check for wave-
form shown in Figure Aat pins B8, B9, B10 and
A9 of Connector CN3 during Form Feed. If wave-
form Is missing, check pins B8, B9, B10 and A9
of Connector CN3 for good connections and
check Interface IC (Q3) on interface Board.
If waveform is present, check for 3.0V at pin
Figure A
12 of Module HiC during Form Feed. If voltage
is not correct, check iC Q3 on Interface
Board. If voltage is correct, check for 12.7V
at base of Transistor TR1 during Form Feed.
If voltage is not correct, check Module HIC.
If voltage is correct, check Transistor TR1,
Diodes DI thru D5, Transistor Array Q1 and
check Line Feed Motor (M1 )windings for conti-
nuity.
RIBBON END SWITCH AND PAPER END SENSOR
Check voltage at pin 1of Connector CN5. The
voltage should be 5.0V with paper in Printer
and Ribbon End Switch not activated. The volt-
age should drop to 0V if there is no paper In
Printer or Ribbon End Switch is activated. If
readings are not correct, check pins 1thru 5
of Connector CN5 for good connections, check
Resistor R12 and check Switch or Sensor that
Is not operating properly.
HOME POSITION SENSOR
Check voltage at pin 8of Connector CN5. The
voltage should be 4.5V when Print Head in Home
position and 0V when head not in home posi-
tion. If readings are not correct, check Re-
sistors R13 and R14, Home Position Sensor
(M5), and check pins 6, 7and 8of Connector
CN5 for good connections.
COLOR RIBBON SENSOR
Check voltage at pin 11 of Connector CN5. The
voltage should be 4.4V with apiece of black
paper inserted in Sensor notch and .1V with no
paper in notch. If readings are not correct,
check Resistors R15 and R16, Color Sensor (M6)

TROUBLESHOOTING (Continued)
and check pins 9thru 12 of Connector CN5 for
good connections. If all the sensors check
good and aproblem still exists, check pins
A13, A14 and B14 of Connector CN3 on Driver
Board and Connector CN1 and IC 03 on interface
Board.
PRINTER WILL NOT RECEIVE DATA (SELF-TEST
WORKS)
Use alogic pulser and logic probe to check
operation of IC 05 and Receive Data Amplifier
Transistor (TR2). Use pulser to inject pulses
at input pins 2, 4, 9or 12 of IC Q5, and
check the corresponding output pins 3, 6, 8or
11 for pulses. To check Transistor TR2, in-
ject pulses at pin 3of Connector CN2 and
check for pulses at collector of TR2. If
pulses are not appearing at outputs of IC Q5,
check for -9.2V at pin 1and 9.2V at pin 14 of
IC Q5. If either voltage is missing, refer to
the "Power Supply" section of this Trouble-
shooting guide. if voltage is good, substi-
tute IC Q5. if pulses are not appearing at
col lector of Transistor TR2, check Capacitor
C4, Diode D7 PTransistor TR2 and Resistors P.2
and R9. If IC Q5 and Transistor TR2 check
good, check CPU IC <Q6) and Interface IC (Q4).
LINE DEFINITIONS
AOTHRU A15 Address BitsOThru 15
ACK Acknowledge, Input Data Received
ALE Address Latch Enable
BUSY Busy, Off Line, Data Entry, Paper Feed, Printing
CE Chip Enable, ROM Memory
COLOR Color Sensor
DO THRU D7 Data BitsOThru 7
DATA LATCH Data Latch
DTR Data Terminal Ready
0¥/2 THRU DW5 Darkness Level Lines 2Thru 5
FAULT Error State
HEAD DRV Print Head Driving Pulses
HOLD MG DRW Hold Print Head, Vertical Positioning
HP Home Position Sensor
l-PRIME Input Prime, Brings Control To Initial State,
Resets System
LF DRV Line Feed Motor Driving Pulses
LMP DRV Lamp Drive, Ready
MDL Paper End/Ribbon End Sensors
OPSW Select Switch Status
PE Paper Empty Sensor
PIW PH1 THRU PM PH4 Carriage Motor/Line Feed
Motor Driving Pulses
RD Read, Memory Or I/O Device
RS/CENTRO Reset
RST Reset Signal To Interface Circuit
RTS Request To Send
SELECT Select Line Indicates On Line Status
SHIFT CLOCK PtycA Head Timing Puses
SHIFT DATA Print Head Printing Pulses
SP DRV Carriage Motor Driving Pulses
SP HOLD Carriage Motor Hold
SPO DRV Carriage Motor Drive Control
SSD Send Data From Printer
STB Strobe
THALM Power Level Status
TXD Transmitted Data
WR Write, Data Bus Info Stored In Memory Or I/O
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