Epson FX-80 User manual

COMPUTERFACTS CP7
EPSON8MODEL FX-80
TECHNICAL SERVICE DATA FOR YOUR PRINTER

SSMSCOMPUTERFACTS
PRELIMINARY SERVICE CHECKS
-This data provides the user with atime-saving service tool
which is designed for quick isolation and repair of printer
malfunctions.
EPSON
MODEL FX-80
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Check all interconnecting cables for good connections and
correct hookup before making service checks.
Replacement or repair of the FMBD Board, Filter Board,
Control Panel or connectors may be necessary after the
malfunction has been isolated.
GENERAL OPERATION
BUZZER TONE CHECKS
Switch Printer On and listen for one of the following pat-
terns of tones: Three short tones and one long tone will in-
dicate an overvoltage detection. Refer to "Power Supply"
section of the Troubleshooting guide.
Three short tones repeated twice indicates aPrinthead (HD)
malfunction. Check to see if the head cable is loose or the
Printhead is not seated firmly on the carriage assembly.
Four long tones indicates one or more of the Printhead
Driver Transistors (Q6 Thru Q14) is shorted, or Printhead is|
damaged. Replace and inspect again.
Five short tones repeated five times indicates paper empty!
signal. If this signal sounds when the Printer is loaded withl
paper, check to see if paper is inserted correctly between]
the lever and switch of PE sensor.
DISASSEMBLY INSTRUCTIONS
UPPER CASE REMOVAL
Remove the brown plastic platen cover, the paper separa-
tor, the Printer lid, and the ribbon cartridge. Remove the
paper feed knob and four screws from cabinet top. Lift
cabinet top up and lay it over to the right side being careful
not to dislodge the control panel connector.
CONTROL PANEL REMOVAL
move one grounding screw (for AC power cord) from chas-
sis. Lift Filter board and power cord retainer from cabinet
bottom.
FMBD BOARD REMOVAL
Disconnect all connectors from FMBD Board. Remove fourl
screws holding FMBD board to cabinet bottom. Release!
two plastic clips and remove board from cabinet.
Disconnect Connector CN7 from the FMBD board. Release
two plastic clips holding Control panel to cabinet top and
remove Control panel through cabinet top.
FILTER BOARD REMOVAL
Disconnect Power Transformer Connector CN1 from Filter
board. Remove one screw holding board at the center. Re-
PRINTER MECHANISM REMOVAL
Remove seven screws holding Printer Mechanism to
cabinet bottom. Disconnect Connectors CN4, CN5 and
CN8 from FMBD Board. Lift Printer Mechanism from
cabinet bottom.
5/iMS Howard W. Sams &Co., Inc.
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. ,Inc. ,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., Inc., 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.
©1985 Howard W. Sams &Co., Inc.
4300 West 62nd Street, P.O. Box 7092, Indianapolis, Indiana 46206 U.S.A.
Printed in U.S. of America. 85CP14948 DATE 4-85

PRELIMINARY SERVICE CHECKS (Continued)
SERVICE CHECKS
SEE INTERCONNECTING DIAGRAM AND PHOTOS TO MATCH THE NUMBER IN THE
CIRCLES WITH THOSE IN THE FOLLOWING DATA FOR SERVICE CHECKS TO BE PER-
FORMED.
©
1.) PRINTER DEAD
©
©
(A) Check AC Fuse (F1). If Fuse is open, disconnect the
power transformer Connector CN6, switch the
Printer On and check for 28.0V AC between pins 1
and 2of Connector CN6 and for 7.6V AC between
pins 3and 4of Connector CN6.
(B) if voltages are missing, check Power Switch
(SW1A), AC Fuse (F1), AC Power cord and also
check Power Transformer (T1) windings with an
ohmmeter.
(C) !f the voltages are present, check the Diode DB1 for
ashort. Replace or Troubleshoot the FMBD Board.
WILL NOT RECEIVE DATA FROM COMPUTER
(A) Check connector cable between the Printer and the
Computer.
(B) Check Connector CN5, check the Printhead cable
for broken or cracked circuits and check the con-
nection at Printhead cable Terminal Board connec-
tor.
PRINTHEAD WILL NOT PRINT
(A) Remove power and check resistance of the Print-
head (HD) Solenoids by removing Connector CN5.
Check the resistance for each solenoid. Each
solenoid should measure about 20 ohms. If the
resistance checks incorrect, replace the printhead.
(B) Check for 24.0V at pins 14, 15 and 16 of Connector
CN5.
©PRINTHEAD HAS MISSING DOTS
(A) Check the resistances of Printhead (HD) solenoids
(20 Ohms). The Solenoid which controls missing
dot will measure incorrectly. If all the Solenoids
measure correctly, check for possible bent or
broken Printhead wires.
(B) Check the Printhead cable for cracks and for good
connection.
(C) If the Printhead is normal, check the
Microprocessor IC (3B) by substitution.
(D) If Microprocessor IC (3B) checks good, replace or
troubleshoot the FMBD Board.
©
5.) PAPER FEED DOES NOT FUNCTION
(A) Check for 22.5V at pins 11 and 12 of Connector CN4
while the Printer is printing.
(B) If the 22.5V is missing, check the 24.0V at TP VP.
(C) Check resistances of the Paper Feed Motor (M4)
windings and replace Motor M4 if defective.
(D) If the Motor M4 checks good, check Connector CN4
for good contacts and also check Microprocessor
IC (3B).
(E) If replacement of IC 3B does not correct the pro-
blem, replace FMBD Board.
@CARRlAGE (TIMING BELT) MOTOR DOES FUNCTION
PROPERLY
(A) Check the timing belt engagement on the bottom of
the carriage assembly.
(B) Check the adjustment of the PTS (Position Timing
Signal) Sensor (M2).
(C) Check the resistance of the windings of Carriage
(Timing Belt) Motor (M3).
(D) Check the adjustment of the Carriage Motor
assembly and check for MINIMUM lash between the
gears without gears locking up.
©POOR QUALITY PRINT
(A) Ribbon Cartridge may be worn and due to be replac-
ed.
(B) See if the ribbon advances and is not jammed. Also
check gear assembly for free movement.
(C) Check the spacing between Printhead (HD) and the
Platen and also check position of the Head Adjust-
ment Lever.
(D) Check for adefective Printhead.
(£) PAPER EMPTY INDICATOR DOES NOT FUNCTION
(A) Check the continuity of the Paper Empty Switch
(SW99).
(B) Make certain Connector CN8 is making good con-
tact.
(C) Make certain Dip Switch (SW1-3) is set in the Off
position.
(D) Check for amalfunction in the control panel by
substitution of Control Panel Assembly.

PRELIMINARY SERVICE CHECKS (Continued)
MECHANICAL REMOVAL AND REPLACEMENT
RIBBON CARTRIDGE REPLACEMENT TIMING BELT REPLACEMENT
Slide Carriage Assembly to center. Move Scale (5-28) to up-
permost position. Turn knob on replacement Ribbon Car-
tridge counterclockwise to tighten ribbon. Install Ribbon
Cartridge with the two tabs at each end fitting into the two
slots of each side frame and the cartridge seated on the
Ribbon Driving Gear (7-3). Do not force it into place. Care-
fully slide Ribbon between Printhead (5-1) and Ribbon Mask
(5-16). Slide Carriage Assembly back and forth to verify pro-
per Ribbon movement.
PRINTHEAD/RIBBON MASK REMOVAL
Remove Platen Cover, Printer Lid and Ribbon Cartridge. If
Printer has been operating, allow Printhead (5-1) to cool.
Slide Carriage Assembly to the left end of Carriage Shafts
to allow access to Head Cable and Head Cable Connector
on the Terminal Board (8-1), Hold Connector in place and
carefully remove the Head Cable from it by pulling on the
plastic tab beneath the Head Cable.
Slide Carriage Assembly to the center position for access
to the Head Lock Lever (5-13). Rotate the lever to the left to
release the Printhead. Lift Printhead straight up to remove
from Carriage Assembly.
Remove the two positioning screws holding Ribbon Mask
(5-16) and lift mask from Carriage Assembly.
Reverse the procedure for replacement. See Printhead Ad-
justment in Miscellaneous Adjustments.
CARRIAGE MOTOR/POSITION-TIME (PTS) SENSOR
REMOVAL
Remove upper case. See Disassembly Instructions. Dis-
connect Connector CN4 from FMBD Board. Remove left-
front screw and right-rear screw from base of Carriage
Motor (2-1). Lift motor assembly out of Printer base. Free
the motor wire harness and separate the Carriage Motor
and Position-Time Sensor wires.
Remove Printer mechanism from case. See Disassembly In-
structions. Press downward on the Timing Belt (4-1) at each
side of the point where belt is attached to Carriage
Assembly. CAUTION: Belt may be held in place with
adhesive cement. If removal is difficult, slide the Carriage
Assembly to the right and over the access hole in the
chassis base. Turn the chassis over. Carefully cut the
adhesive seal with arazor blade and remove the belt from
the Carriage Assembly with needle-nose pliers.
Loosen the screw securing the Belt Tension Plate (4-5) and
remove the Timing Belt from the belt-driven pulley. Remove
the left-front screw and right-rear screw from the Carriage
Motor (2-1). Lift the motor assembly from the Printer base
for access to the belt drive pulley. Remove belt from pulley.
Push belt through opening in right frame and remove belt
from Printer.
Install replacement by reversing the removal procedure. Be-
fore adjusting tension, apply adrop of adhesive cement I
where Timing Belt is attached to Carriage Assembly and
allow to dry. See Timing Belt Adjustment in Miscellaneous |
Adjustments.
BELT TENSION PLATE REMOVAL
Remove upper case. See Disassembly Instructions. Slide
Carriage Assembly all the way to the right. Loosen the nut
on each end of the front Carriage Shaft (5-17). Remove the
left end of the Carriage Shaft from the side frame. Remove
the adjustment screw from the Belt Tension Plate (4-5) and
lift the Timing Belt (4-1) from the belt-driven pulley. Lift the
Tension Plate up and out of the Printer base with ribbon
driving gears intact.
Reverse the procedure for replacement. See Timing Belt |
Adjustment in Miscellaneous Adjustments.
PAPER FEED MOTOR/TRANSMISSION GEAR
REMOVAL
Remove the screw holding the Position-Time Sensor Board
(3-7) to the motor base and remove Sensor Board from Car-
riage Motor heat sink. Remove right-front screw and left-
rear screw from the motor base to remove the Carriage
Motor and Sensor Disk from the heat sink.
Reverse the procedure for replacement. See PTS Sensor
Board Adjustment in Miscellaneous Adjustments.
HOME POSITION SENSOR REMOVAL
Remove Platen Cover, Printer Lid and Ribbon Cartridge.
Slide Carriage Assembly to the right end of Carriage Shaft
to access the Home Position Sensor Connector on the Ter-
minal Board (8-1). Disconnect Connector and remove screw
holding Sensor Board. Lift Sensor Assembly out of Printer
base.
Reverse the procedure for replacement. See Home Position
Sensor Adjustment in Miscellaneous Adjustments.
Remove upper case. See Disassembly Instructions. Dis-
connect Connector CN4 from FMBD Board. Remove three
screws from base of Paper Feed Motor (2-3). Remove motor
from chassis side frame. Free the motor wire harness and
separate Paper Feed Motor wires from harness. Pull Trans-
mission Gear (5-3) straight out from side frame and off of
gear shaft pin. Retain thrust washer used on inner side of
gear.
Reverse the procedure for replacement. Slide motor up to
minimize gear lash but do not lock up gears. Perform self-
test to check proper paper advancement.
SCALBPAPER HOLDING LEVERS REMOVAL
Remove upper case. See Disassembly Instructions. Re-
move two screws holding Platen Cover (6-2). Carefully lift
cover backward and upward to clear the lever on the Paper
Empty Sensor. Loosen the screws at the end of the Scale
(5-28). Remove the E-rings and Springs (5-23) from the Paper
III

PRELIMINARY SERWiCE CHECKS (Continued)
MECHANICAL REMOVAL AND REPLACEMENT (Continued)
Holding Lever Assembly. Lift up the Scale and Paper
Holding Levers to remove them from the side frames. Keep
the two Lever Springs (5-21) (5-26) released at this point with
the assembly. Reassemble in reverse order.
FRICTION/SPROCKET PLATEN REMOVAL
Perform Paper Feed Motor/Transmission Gear Removal and
Scale/Paper Holding Levers Removal procedures. Remove
the nuts on the ends of the Sprocket Guide Shaft (5-3). Re-
move the E-ring from the left shaft end of the Platen
Assembly (5-2). This will release the Left Bearing (5-4), flat
washer and thrust washer. Push the Left Bearing outward
and slide the Platen Assembly toward the right. When bear-
ings are clear of side frames, lift Platen Assembly out of
chassis.
To remove Left Sprocket Assembly (5-6), slide the assembly
off the left end of the Platen Assembly and Sprocket Guide
Shafts. To remove Right Sprocket Assembly (5-7), remove
the Spring Pin (SP) holding the Platen Gear (5-3), plain
washer, leaf spring, Spacer (5-5) and Right Bearing (5-4).
Slide the assembly off the right end of the Platen Assembly
and Sprocket Guide Shafts.
TRACTOR REMOVAL
Remove seven screws holding tractor to cabinet bottom.
Disconnect Connectors CN4, CN5 and CN8 from FMBD
Board. Lift tractor assembly from cabinet bottom.
PAPER EMPTY SENSOR REMOVAL
Remove upper case. See Disassembly Instructions. Dis-
connect Connector CN8 from the FMBD Board and free
wires from restraining hook next to Sensor. Release Spring
(3-2) and carefully bend back the holding tab at lower edge
of Sensor board. Lift board from the Paper Guide
Assembly. To remove the Sensor Lever (3-1), remove the
E-ring and Shaft (3-3) from the lever. Reassemble in reverse
order.
TEST EQUIPMENT AND TOOLS REPLACEMENT PARTS
TEST EQUIPMENT ITEM NO. PART NO. DESCRIPTION
Digital Volt/Ohm Meter
Logic Probe
Oscilloscope
TOOLS
Phillips Screwdriver
Low Voltage Soldering Iron
Desoldering Tool
Small Screwdriver
DB1 X340300010
F1 X502060020
HD
IC3B Y440804101
M3 F31 5059000
M4 F31 5064000
SW1 X620400580
SW1A
SW99 A1 70202502
T1 Y440501000
4-1 F303014010
Diode, Rectifier
AC Fuse, 2A
Printhead (Includes Solenoids)
IC, Microprocessor
Motor, Carriage (Timing Belt)
Motor, Paper Feed
Switch, Dip
Switch, Power
Switch, Paper Empty, Reed
Transformer, Power
Control Panel Assembly
FMBD Board
Filter Board
Timing Belt
IV

PRELIMINARY SERVICE CHECKS (Continued) PRELIMINARY SERVICE CHECKS (Continued)
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120VAC
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POLARIZED
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POWER SWITCH
SW1A
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PAPER EMPTY r(8A
SWITCH .
SW99 '--
IC1 16
19-
CN1
7.6 VAC
CN6
DB1 ?(1C
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28.0VAC (SB)
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24.0V
MICROPROCESSOR
1C3B
FMBD BOARD
1C) (4D) (5E)
18
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(8B)
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CN8 r2Tmj6^24.0V
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22.5V(5A)
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(26) (3A CN4 11 18
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(7B)
RIBBON
CARTRIDGE
GEAR
ASSEMBLY
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TIMING BELT
24.0V
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PRINTHEAD
HD
10 5S11 12 76913 IS
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FLEXIBLE CABLE
TERMINAL
BOARD CONNECTOR
(5)
FRONT CARRIAGE SHAFT
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ON OFF
SW2
CN4-8
PAPER FEED
MOTOR
M4
CN4-10
INTERCONNECTING DIAGRAM
-mINTERCONNECTING DIAGRAM
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PRELIMINARY SERVICE CHECKS (Continued) PRELIMINARY SERVICE CHECKS (Continued)
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PRELIMINARY SERVICE CHECKS fContlnued)
MISCELLANEOUS ADJUSTMENTS
HEAD DRIVER PULSE WIDTH ADJUSTMENT
Connect the input of ascope to pin 36 of the Micro-
processor IC (3B). Set the horizontal sweep to .1ms, trigger
to positive edge. Use the Printer self-test mode (hold LF
Button down while switching Printer On) and adjust the
Pulse Width Control (VR1) for apulse width of .62ms, See
Figure 1.
Figure 1
PTS SENSOR BOARD ADJUSTMENT
Connect the input of ascope to TP PTS, set the horizontal
sweep to .5ms, trigger to positive edge. Use the Printer self-
test mode (hold LF Button down while switching Printer
On). Loosen the screw holding the PTS (Position Timing
Signal) Sensor board to the right side of the Carriage Motor
(M3). Use ascrewdriver in the slot provided to adjust the
PTS Sensor Board for apulse cycle of 2.1ms, or a50% Duty
Cycle while the Printer is printing in both directions. See
Figure 2.
Figure 2
HOME POSITION SENSOR ADJUSTMENT
Loose the HP (Home Position) Sensor screw. Use a small
flat screwdriver to move the notch at the front of the HP
Sensor Board. Move the notch to the left to move the
margin left or to the right to move the margin right. Install
the Ribbon Cartridge and perform aself-test to test the
margin position. Repeat this procedure until printing
begins at the desired position on the paper, tighten the Sen-
sor screw.
TIMING BELT ADJUSTMENT
Loosen the adjustment screw on the belt tension plate.
Tighten the belt until no more than 1/4 inch movement oc-
curs on the Printhead when it is at either end of the carriage
shaft and the belt is pressed inward. Tighten the adjust-
ment screw on the belt tension plate. Run the printer in
self-test mode and note the distance between characters.
The distance should be the same. If not, check the timing
belt by substitution and perform the carriage motor adjust-
ment.
CARRIAGE MOTOR ADJUSTMENT
Loosen the left-front and right-rear screws on the Carriage
Motor (M3) base. Slide Motor M3 toward the front of the
Printer to decrease the gear lash. This is done to MINIMIZE
the gear lash, without locking the gears tightly together.
Slide the motor (M3) toward the rear of the Printer to in-
crease the distance between the gears. Tighten the screws
of the Carriage Motor base and set the Printer in self-test
mode to verify consistent speed of the carriage assembly in
both directions.
PRINTHEAD ADJUSTMENT
Remove the Printhead (HD) and the Ribbon Mask. Reinstall
the Printhead and lock it into position with the Ribbon Mask
off. Turn the rear carriage shaft until the widest portion of
the hole on the left end of the shaft is upward. Insert athin
screwdriver through the hole to hold the shaft in position
and loosen the nut at the left end of the shaft. Set the Head
Adjustment Lever to center position and hold in place.
Move the Printhead to the middle of the shaft and insert a
0.6mm Feeler Guage between the Printhead and the Platen.
Turn the shaft forward or backward until the gap between
the Printhead and Platen is correct. Hold the shaft in place
and tighten the nut on the left end of the shaft. Check the
adjustment by gauging the gap at the left and right sides
and at the center of the Platen. Move the head adjustment
Lever toward the Platen and remove the Printhead. Re-
install the Ribbon Mask with a0.3mm gap between the
mask and the Platen and tighten the two screws on the
mask. Reinstall the Printhead and check for agap of about
0.1mm between the Ribbon Mask and the Printhead. Re-
install the ribbon cartridge and perform Printer self-test
with the Head Adjustment Lever set to mid-position. The
print should be clear and dark without the wires of the Print-
head perforating the paper.
DIP SWITCHES O
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SWITCH SW-1 ON OFF r- £
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1-1 Column length 132 characters 80 characters §
/line /line
1-2 ZERO Font slashed not slashed
1-3 Paper empty Inactive Active
detector
1-4 Input buffer Standard ASCII
Accessed inactive
1-5 Character mode Emphasized Standard
Power ON
INTERNATIONAL CHARACTER SET DESIGNATION
SW1-6 SW1-7 SW1-8
USA ON ON ON
England ON OFF OFF
France ON ON OFF
Germany ON OFF ON
SW1-8 SW1-7 SW1-8
Denmark OFF ON ON
Italy OFF OFF ON
Spain OFF OFF OFF
Sweden OFF ON OFF
SWITCH SW-2 ON OFF
2-1 Select Mode Fixed Select Can be selected
by Computer
2-2 Buzzer Buzzer No Buzzer
2-3 Lower margin Margin No Margin
one inch
2-4 Auto line feed Auto Line Feed Line feed from
with Carriage Host Computer
Return
sx

PRELIMINARY SERVICE CHECKS (Continued)
1.20VAC
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FILTER BOARD

PRELIMINARY SERVICE CHECKS (Continued)
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