JUKI TL-98E User manual

R
SERVICE MANUAL
TL-98E
1-NEEDLE LOCKSTITCH SEWING MACHINE WITH
AUTOMATIC THREAD TRIMMER FOR PROFESSIONAL
293-27707

C O N T E N T S
[1] SPECIFICATIONS OF TL-98E........................................................................ 1
[2] PRINCIPLE OF ELECTRIC BRAKE............................................................... 2
[3] NAMES OF COMPONENTS ........................................................................... 3
[4] DISASSEMBLY AND ASSEMBLY ................................................................. 3
[5] PRINTED CIRCUIT BOARD DIAGRAM (CONNECTOR LAYOUT)............. 15
[6] ADJUSTMENTS OF COMPONENTS ........................................................... 16
WARNING :
To avoid the risk of fire, electric shock, injury to persons or damage to components, especially keep the
following :
• When disassembling, assembling or adjusting the sewing machine, remove the power plug.
• When assembling, be careful about the electrical cord being caught with other components, damage
to the covered parts of the cord or miswiring.
• When replacing the part(s), use the genuine part(s).

–1 –
[1] Specifications of TL-98E
(1)Speed control device
Foot controller method : 80 to 1,500 rpm
(2)Table and stand components
Main unit : Portable type main unit with soft case (Case is folded in two and packed with main unit.)
One-touch type auxiliary table knee lifter is provided as standard. (Packed together)
Handle : Pull-up/down from machine main unit type
(3)General mechanism
1. Thread take-up : Slit type link thread take-up for one-touch threading
2. Hook : DB type horizontal full-rotary hook
3. Pressing pressure adjustment : Stepless adjusting screw with pressing pressure indicator method
4. Lighting device : Built in face cover Switch : Slide type
Lamp ...... Halogen lamp
5. Needle thread post : Thread guide of thread post is of tilting type and capable of one-touch
threading
6. Bobbin thread winder : One-touch action : Starting method by controller Automatic stop
when bobbin thread winding completed
7. Power switch : ON/OFF 2-step method
8. Lift of presser foot : By lever : 7 mm Max. by lever : 10 mm By knee lifetr : 12 mm
9. Thread tension : Disk pressure adjusting type with simplified disk pressure scale
10. Drop feed : 2-step changeover by knob method (Feed dog : UP : DOWN)
(4)Feed mechanism
1. Feed amount adjustment : Dial method ......Stepless 0 to 6 mm
2. Reverse feed stitch : Lever method ...... Feed amount conforms to that of normal feed stitch.
(5)Special mechanism
1. Automatic thread trimming : Thread trimming switch is used in common for pushbutton type and
for external foot pedal switch type.
2. Needle bar stop position : Electric brake stop method
Stop by controller : Down stop
Stop by automatic thread trimming : Up stop
Stop by bobbin winder : Up stop
3. Needle up/down switch : Switch is of pushbutton type and up/down stop by half rotation of
main shaft
4. Prevention of reverse setting of needle : Needle is attachable to normal direction only.
5. Motor protection
Overcurrent : When motor is locked for approximately one second due to sudden overload, motor power
is automatically turned OFF and returns to the ON state immediately.
Overheat : When motor temperature has abnormally risen, motor power is turned OFF (thermal cut)
and returns to the ON state when temperature has fallen.
(6)Dimensions and weight
Main unit : 452W x 219L x 319H (mm)
Weight : 11.3kg
(7)Power consumption
Whole sewing machine : 120V 1.4A/60Hz
Lamp : 12V 3W (Halogen lamp)

–2 –
[2] Principle of Electric Brake
Three lead wires are drawn out from the motor. Lead wire is drwan out from the connecting point of the rotor coil
and stator coil to use the electric brake. MP detection printed circuit board asm. detects the number of slits of
the shield plate fixed on the motor shaft and is used to calculate the number of rotations of the motor and the
phase of main shaft. There are 72 pcs. of slits on the shield plate per circle. If the slit is converted into the main
shaft angle, the position can be measured (calculated) in a unit of 0.4 degrees. Comparing with the conventinal
model, the number of slits are increased and unevenness of rotation can be controllable. Principle of the
electric brake is called dynamic braking. The rotor becomes the dynamo and generates the electric power while
motor is rotating. Electric brake makes use of the fact that the brake is applied to the motor by consuming this
electric power. The higher the number of rotations becomes, the more the brake force becomes and the lower
the less.
Motor drive simplified diagram
At the time of normal rotation of motor
Brake : Off
Motor drive : ON/OFF
Motor drive : Full wave phase control
: Motor drive ON
At the time of motor brake
Brake : ON
Motor drive : Oscillation
Motor drive : Oscillation
At the time of inertia stop or
normal stop of motor
Brake : OFF
Motor drive : OFF
Motor drive : OFF

–3 –
[3] Names of Components
[4] Disassembly/assembly
Page
Outer Components
1. Arm cover asm. ...................................... 4
2. Belt cover and motor cover .................... 4
3. Face plate asm. ...................................... 4
4. Bed cover mas. asm. ..............................5
5. MAIN circuit board asm. ......................... 5
Function components
1. Motor asm. and transformer asm. .......... 5
2. Handwheel and clutch ............................ 6
3. Thread tensioner asm. ........................... 6
4. Presser bar ............................................. 7
5. Needle bar .............................................. 7
6. Thread take-up ....................................... 8
7. Reverse feed stitch lever ........................ 8
8. Idler ........................................................ 8
9. Stitch dial ................................................ 9
10. Automatic thread trimming switch case .. 9
Page
11. Wire holder ............................................. 9
12. Knee lifter lever ..................................... 10
13. Hook driving shaft pulley ......................... 11
14. Hand lifter lever ..................................... 12
15. Drop-feed knob ..................................... 12
Automatic thread trimming components
1. Looper mas. asm. ................................. 13
2. Moving knife arm
installing plate mas. asm. ..................... 13
3. Thread trimming solenoid mas. asm. ... 14
4. Moving knife base mas. asm. ............... 14
Indicating needle of
presser spring regulator
Face cover
Pressure indicating plate
Thread take-up thread guide
Lamp switch
Thread take-up spring
Presser bar connection thread guide
Lamp bulb
Hand lifter lever
Needle bar thread guide
Needle bar thread bracket
Presser spring regulator
(Hole for auxiliary table support plate)
Thread guide base
Side cover
Thread guide No. 1
Standard presser foot asm.
Arm cover asm.
Throat plate asm.
Bobbin winder shaft
Thread take-up spring adjusting plate
Belt cover
Handwheel
Stitch dial
Needle up/down switch
Automatic thread trimming switch
Reverse feed stitch lever
Hole for knee lifter lever setting
Bed cover rubber seat
Bed cover
Drop-feed knob
(Hole for auxiliary table support plate)

–4 –
1. Arm cover asm.
3. Face plate asm.
Preparation
™Remove arm cover.
2. Belt cover and motor cover
Outer Components
1Arm cover setscrew
SM5042005SN
3Arm cover
6Convex of presser
spring regulator knob 5Slit of presser regulating screw
4MAIN circuit board case cover
2Bobbin winder connector
Point
™There should be no difference in
level between belt cover and front
face of frame.
™Make motor cover come closely
contact with belt cover.
Disassembly
Remove four setscrews of 1and
remove belt cover.
Remove three setscrews of 2and
remove motor cover.
Assembly
™Attach belt cover and tighten
setscrews.
™Attach motor cover and tighten
setscrews.
Point
™There should be no torsion or
distorsion in presser spring
regulator.
™Align precisely slit portion with
convex portion.
™Do not press each lead wire.
Disassembly
Remove two setscrews of 1.
Disconnect and remove connector of
2.
Remove MAIN circuit board case
cover of 4.
Assembly
Attach case cover of 4.
Insert connector of 2.
Align convex of 6with slit of 5and
tighten the setscrew.
3Face plate asm.
1Lamp connector
5Face cover
2Face plate asm. setscrew
SL5040631SE
6Hand lifter lever spring
4Indicating needle of
presser spring regulator
Point
™There should be no difference in
level around the cover when face
cover is closed.
™5shouldnot come in contact with
indicating needle of 4.
Disassembly
Disconnect 1connector and remove
6.
Remove setscrews of 2and remove
3face plate asm.
(together with face cover).
Assembly
™Attach face plate asm. and tighten
setscrews.
™Insert connector.
2Motor cover setscrew
SM5041255SN
1Belt cover setscrew
SM5041255SN

–5 –
5. MAIN circuit board asm.
Preparation
™Remove arm cover asm.
Note) Setscrew to set the
circuit board and cover
to circuit board case
Do not insert in the
reverse direction.
(See page 15.)
Do not loosen
this screw.
4. Bed cover mas. asm.
1. Motor asm. and
transformer asm.
Preparation
™Remove arm cover asm.
™Remove belt cover and
motor cover respectively.
Make a memorandum of
cord wiring.
PointDisassembly
Remove six setscrews of 1and
remove bed cover.
Assembly
™Attach bed cover and tighten
setscrews.
1Bed cover setscrew
SM5051255SN
1Bed cover setscrew
Point
™Read the note and understand it.
™Ther are color indications on the
circuit board for inserting
connectors.
Disassembly
™Remove 10 connectors of each
lead wire.
Remove lead wire from mini-clamp of
1.
Remove setscrews of 2and 4, and
remove circuit board.
Assembly
Attach circuit board and tighten
setscrews.
™Insert each lead wire into
connectors.
3MAIN circuit board
setscrew
4MAIN circuit
board case
setscrew B
SM5031401SE
Porality exists.
Never loosen this screw.
2MAIN circuit board case setscrew A
SL5030831SF
5Cord guide
plate setscrew
SM5030655SN
1Mini-clamp
(4 places)
Cord guide
plate asm.
Point
™Loosen nuts of 3to adjust motor
tension.
™Belt tension : the belt should sag
3 to 4 mm when center of belt is
applied with 1.96N load.
Disassembly
™Cut clip band of 5cord guide
plate asm. in previous item.
Remove two setscrews of 1and
remove motor asm.
Remove two setscrews of 2and
remove transformer asm.
Make sure of wiring route.
Assembly
™Attach transformer and tighten
setscrews.
™Attach motor asm. and tighten
setscrews.
™Attach cord guide plate asm. and
tighten setscrew.
Function Components
2Power transformer
setscrew
SM5040855SN
3Motor setscrew nut
1Motor asm.setscrew
SM5050855SN
Position of cable

–6 –
2. Handwheel and clutch
Preparation
™Remove belt cover.
3. Thread tensioner asm.
Disassembly
Remove setscrew of 1.
Remove cord guide plate setscrew
and remove cord guide plate asm.
Remove spring support of 3.
Move 4in the direction where clutch
spring is released and remove clutch
spring.
Face 6to motor side and 8is hard
to drop.
Draw out 8and remove 9.
Assembly
Attach 9and enter 8.
™Enter groove 6of bushing to
stopper pin 8and attach bushing.
™Enter hook portion 5of spring to
slit in the center of handwheel
bushing
™Enter clutch spring 5to groove
3of spring support and attach
cord guide plate asm. Then
tighten setscrew.
Point
™Align convex 7of bushing with
groove !0 of handwheel and
attach handwheel. Then tighten
setscrew.
Clearance provided between convex
of clutch spring support 3and clutch
plate is 2 ±0.5 mm.
See item 12 on page 19 for adjustment.
1Handwheel
setscrew
2Handwheel
9Motor pulley
6Groove of handwheel
bushing
8Handwheel bushing stopper pin
4Angle portion of clutch spring
7Convex of handwheel bushing
5Hook portion of clutch spring
3Groove of clutch spring support
!0 Groove of handwheel
Disassembly
Remove setscrew of 1.
™Lower presser foot and remove
setscrew of 2.
Remove spring of 3together with
thread tensioner asm. of 4and
adjusting plate.
Assembly
™Attach adjusting plate and spring
3to thread tensioner asm. and
attach it to frame. Then fix it with
setscrew of 2.
™Tighten adjusting plate setscrew
1.
Point
™Place upward the scale of thread
tension disk presser 5.
™See items 9 and 10 on page 18
for adjustment of pressure and
stroke of thread take-up spring.
1Thread take-up spring
adjusting plate setscrew
SL5030801SN
2Thread tensioner setscrew
SM8040602TP
3Thread take-up spring
4Thread tensioner asm.
5Thread tension disk presser

–7 –
4. Presser bar
Preparation
™Remove arm cover asm.
™Remove face plate asm.
™Remove presser foot and setscrew.
5. Needle bar
Preparation
™Remove arm cover asm.
™Remove face plate mas. asm.
™Remove presser bar.
Disassembly
Lower lever of 8and loosen
setscrew of 1.
Remove regulator screw of 2.
Drawing 3upward, remove spring of
4.
Remove connection of 5and lever
of 6.
Do not remove indicating needle of
7.
3is hard to remove since secrew
mark is attached.
Assembly
™Set lever 6to frame, and then set
connection 5.
™Attach spring 4when setting
presser bar 3from upper side.
™Attach regulator screw 2.
Point
™Set spring 4under indicating
needle 7.
™Lower lever 8and temporarily
tighten it at the position where top
end of 3protrudes approximately
4 mm from frame.
For the adjustment, see item 3 on
page 17.
™Needle should not interfere with
presser foot.
Disassembly
Remove 3and 4.
Remove felt of 1.
Loosen setscrew of 2. (Pushing
needle bar 5upward is acceptable.)
Draw out 5upward.
Remove left screw of 6and remove
crank rod.
Assembly
™Attach crank rod and tighten it with
6.
™Perform positioning of needle bar
and tighten needle bar connection
setscrew 2.
™Set needle bar and attach 4, 3
and 7.
Point
™Position of needle bar is the place
where upper engraved line of
needle bar is aligned with lower
end face of needle bar bushing at
the needle lower dead point.
See item 2 on page 16 for the
adjustment.
6Needle bar crank left screw
5Needle bar
1Needle bar upper
bushing felt
2Needle bar connection setscrew
SM8060510SP
4Needle clamp
3Needle bar thread bracket
setscrew A1420-001-000 7Needle mis-insertion preventing plate
6Presser bar lifting lever
8Hand lifter lever
3Presser bar
2Presser spring regulator
7Indicating needle of
presser spring regulator
4Presser spring
5Presser bar connection
asm.
1Presser bar connection
setscrew
SM8060502TP

–8 –
7. Reverse feed stitch lever
Preparation
™Remove belt cover.
(Remove motor cover.
™Remove motor mas. asm. )
8. Idler
Preparation
™Remove belt cover.
™Remove motor cover.
™Remove motor mas. asm.
Disassembly
Remove setscrew of 1and remove
idler asm.
Assembly
™Assemble idler and tighten it with
setscrew 1.
™Belt tension : Belt sags 6 to 7 mm
when center of the belt is applied
with a 1.96N load.
Point
™Belt tension can be changed only
by removing belt cover. Move
convex portion of 2to the left or
right.
Disassembly
Remove spring of 1from arm.
Remove two setscrews of 2.
Remove lever arm 4from the slot of
regulator 5when removing 3.
Assembly
™Attach lever 3and set with
setscrews 2.
™Hook lever spring 1to lever arm
4.
Point
™Set lever arm 4to the slot of
regulator 5.
Disassembly
Loosen setscrew of 1.
Loosen two setscrews of 2.
Draw out thread take-up supporting
shaft 3.
Remove 5and 6together with
needle bar crank of 4.
Assembly
™Set needle bar crank to thread
take-up, attach it onto main unit
and tighten setscrews (2 pcs.).
™Set 6to 5, enter thread take-up
supporting shaft 3to 6, attach it
onto frame and tighten setscrew
1.
Point
™Tighten setting portion (flat
portion) of needle bar crank with
screw No. 1.
™Press shaft3to frame side while
viewing the torque and tighten
setscrew 1.
6. Thread take-up
Preparation
™Remove arm cover asm.
™Remove face plate mas. asm.
™Remove presser bar.
™Remove needle bar.
2Convex portion of idler installing plate
1Idler setscrew
SM5040855SN
5Feed regulator
1Reverse feed
stitch lever spring
4Reverse feed
stitch lever arm
3Reverse feed stitch
lever mas. asm.
2Reverse feed stitch lever setscrew SM5040855SN
2Needle bar
crank setscrew
5Thread take-up
1Thread take-up
supporting
shaft setscrew
SM8050602TP
6Thread take-up
support
3Thread take-up supporting shaft
4Needle
bar crank

–9 –
9. Stitch dial
Preparation
™Remove arm cover asm.
10.Thread trimming switch case
Preparation
™Remove arm cover asm.
™Remove motor cover and belt cover.
™Remove motor mas. asm. 1Thread trimming switch
circuit board case setscrew
SL4040655SN
11.Wire holder
Preparation
™Remove outer components.
(Excluding belt cover and motor cover)
™Remove presser bar.
1Nut of setscrew
(opposite side 9 mm)
NS6620310SP
2Wire tube presser
setscrew
SM4040655SN
3Feed regulating screw
stopper asm. setscrew
5Feed regulating screw
• Stopper screw
• Stopper nut
Disassembly
Loosen two setscrews of 1and
remove the dial.
Be careful since pin of 2jumps.
3may not be removed.
(Stopper screw SM8031400TP)
Assembly
™Turn regulating screw 4full to the
right.
™Assemble stitch dial with its scale
0 up and tighten screw 1(2 pcs.).
Point
™There should be no play in feed
regulator when operating lever.
(When scale is 0.)
™Loosen stopper nut of 5. Make
stopper screw strike against
regulating screw 4and tighten
nut.
2Feed regulating
pin
1Stitch dial setscrew
SM8030402TP
4Feed regulating screw
Disassembly
Remove two setscrews in 1thread
trimming switch case.
™Remove thread trimming switch
case.
Assembly
™Attach the switch case to frame
and tighten with setscrews 1.
Point
™There should not be no torsion
between switch and frame.
3Wire holder setscrew
SM5040855SN
5Disk pressure release
connecting link
4Thread release plate

–10 –
12.Knee lifter lever
Preparation
™Remove outer components.
(Excluding belt cover and motor cover)
™Raise presser foot.
Disassembly
Remove snap pin of 4.
Remove setscrews of 5and remove
6.
Remove setscrew of 1and take out
lever spring.
Lower 2and turn it to the position
where 3can be removed.
Remove 3and actuating plate, and
draw out 2.
Remove claw lever shaft setscrew of
7.
Remove link asm. of 8.
Assembly
™Attach 8to frame and tighten
setscrews 7.
™Set lever shaft 2, attach claw
lever actuating plate and tighten
it with 3.
™Attach lever spring and tighten
with 1.
™Raise frame, attach knee lifter
lever 6and tighten it with 5.
™Enter snap pin 4.
Point
™There should not be a play in the
axial direction of knee lifter lever
shaft 2.
Note) 1to 3may be deleted.
Disassembly
Remove nut of 1(left side only).
Remove setscrew of 2and remove
tube presser.
Remove setscrews of 3and remove
wire holder mas. asm.
When removing the wire from
frame, make sure of wire route in
frame.
Assembly
™Lay wire in frame.
™Assemble wire holder mas. asm.
and tighten with setscrews 3.
™Fix 2and 1in the reverse side
of machine bed.
Point
™Pass the wire through full reverse
side of stitch dial.
™Contact4and 5with each other.
™Tube presser and tube regarding
2should be on the same face.
See item 5 on page 23 for 1.
1Knee lifter lever shaft spring setscrew
SM5030455SF
6Knee lifetr lever
5Knee lifter lever shaft stop
plate setscrew
SM5040855SN
4Knee lifter link snap pin
2Knee lifter lever shaft
8Knee lifter link asm
(claw lever plate)
7Claw lever shaft
setscrew
SM5041255SN
3Claw lever actuating plate
setscrew SM8040602TP

–11 –
13. Hook driving shaft pulley
Preparation
™Remove outer components.
(Excluding stop solenoid)
™Loosen idler.
™Remove needle.
8E-ring groove
6
4
5
Make 7hook driving shaft pulley
come out downward.
!0 Moving knife
roller arm
!1 Thread trimmer cam
2Hook driving shaft pulley eccentric shaft
setscrew
SM8040602TP
Hexagon 2.0 mm
5Hook driving shaft pulley eccentric shaft
9Thread trimmer
cam screw No. 1
3Hook driving shaft
pulley
E-ring (E-6) 6Hook driving shaft pulley eccentric
shaft bushing
Slit on 4hook driving shaft pulley
eccentric shaft
1Timing belt
AB
Disassembly
™Remove timing belt from main
shaft pulley.
Remove belt of 1and loosen two
setscrews of 2.
Remove E-6 of 3and turn 4to find
a place where backlash in hook
driving shaft pulley is large.
Press 5and push out bushing of 6
to the right side.
Draw out 5and 6, and remove 7
following the point of 7.
Do not make a flaw on E-ring
groove 8when removing E-ring
3.
Assembly
™Enter hook driving shaft pulley
7.
™Enter eccentric shaft 5and 6.
™Set E-ring 3.
™Remove the play in hook driving
shaft with6and tighten setscrew
2B.
™Turn shaft slit 4to adjust
backlash in pulley and tighten
setscrew 2A.
™Set belt 1.
Adjust backlash in eccentric shaft
by right rotation.
Point
When setting bushing 6, do not
make a flaw on the end face of
bushing.
When setting belt onto main shaft,
refer to thread trimming timing.
(Simple method)
™Lower needle bar 1.93 mm from
its upper dead point.
™Turn hook driving shaft and orient
screw No. 1 9to this side (just
front).
™Enter contact of roller arm !0 to
groove of cam !1.
™Turn hook driving shaft in the
reverse direction and set belt at
the position where it stops.
(Illustration of hook driving shaft pulley)

–12 –
15. Drop-feed knob
Disassembly
Set drop-feed knob 1to “NOT
FEED” and remove drop-feed
adjusting arm spring 2.
Remove E-ring 3of knob shaft.
Remove knob shaft setscrew 4and
draw out drop-feed knob.
Assembly
Pass drop-feed knob through wire
installing plate 5on frame and enter
E-ring.
Insert drop-feed adjusting arm asm.
6, press it to E-ring 3, remove the
play and tighten it with setscrew 4.
Point
It is easy to remove spring 2when
drop-feed knob 1is set to “FEED”
side.
3
5
2
6
44
1
14. Hand lifter lever
Disassembly
Enter 3 to 4 screw threads of M4
screw (arm cover setscrew) in the
hole of hand lifter lever shaft on
frame.
Hold screw head and draw out the
screw. At the same time, hand lifter
lever shaft 2is drawn out.
Remove hand lifter lever 1.
Assembly
Enter hand lifter lever shaft 2into
the hole on frame.
Tap head of lever shaft to fit the shaft
by force and set the shaft to hole in
hand lifter lever.
Point
End face of lever shaft that is fit by
force should not be convex from
frame face.
1Hand lifter lever
2Hand lifter lever shaft
3M4 screw

–13 –
Automatic Thread Trimming Components
1. Looper mas. asm.
Preparation
™Remove bed cover.
2. Moving knife arm installing plate mas. asm.
Preparation
™Remove bed cover.
™Remove looper link asm.
(See 3of the previous item.)
™Remove moving knife arm spring.
(See 4of the previous item.)
3Nut (9 mm) of
wire setscrew
1Moving knife link shaft A
E-ring E-4
6Moving knife link
5Moving knife arm installing
plate mas. asm. set screw
SM4050855SP 4Knee lifter lever shaft setscrew
SM5030455SF
2Thread trimmer solenoid link B
E-ring E-4
Disassembly
Remove E-ring of 1. Do not
remove moving knife link of 6.
(Remove it together with moving knife
installing plate.)
Remove E-ring of 2and remove
thread trimmer solenoid link B.
Remove only left-side nut of 3.
Loosen setscrew of 4.
(To increase operability of 5)
Remove two setscrews of 5and
remove installing plate mas. asm.
At this time, simultaneously
remove moving knife link.
( To prevent warp of moving knife
link)
Assembly
™Attach moving knife arm installing
plate mas. asm.
Note : See the point on the right side.
™Temporarily tighten setscrews
5.
™Attach E-ring 1of link shaft.
™Attach thread trimmer solenoid
link B and set with E-ring 2.
™Attach moving knife arm spring.
™Determine position of moving
knife and securely tighten 5.
Note : See the point on the right side.
™Raise knee lifter lever shaft by
hand and tighten lever spring
setscrew 4.
Point
™Set moving knife link 6and wire
setscrew.
™Position of moving knife
Remove hook and see from the
reverse side of bed.
(See item 1 on page 21.)
™See item 1 on page 21 for
adjustment of nut 3of wire.
5Looper mas. asm.
setscrew
SM5040855SN
3Looper link asm.
2Looper link holding shaft
(Washer A1731090000
E-ring E-3)
4Moving knife
arm spring
1Looper link B
E-ring E-3
Disassembly
Remove E-ring of 1.
Remove E-ring and washer of 2.
Remove looper link asm of 3.
Remove moving knife arm spring of
4.
Remove setscrews of 5and remove
looper mas. asm.
Assembly
™Attach looper mas. asm. and
tighten setscrews 5.
™Hook moving knife arm spring
4.
™Set looper link and attach E-ring,
washer, etc.
Point
™Place looper 6in the center 7
of inner hook and securely tighten
5.
See item 4 on page 23 for
adjustment of looper moving
amount.
7Bobbin case
(Center of inner hook)
6Looper

–14 –
Disassembly
Loosen pin setscrew of 1.
Pull solenoid link A of 2to the right
and remove it from solenoid shaft.
Remove two setscrews of 3and take
thread trimmer solenoid.
Assembly
™Attach thread trimmer solenoid
and temporarily tighten it with
setscrews 3.
™Contact thread trimmer solenoid
pin and shaft with each other.
™Attach thread trimmer solenoid
link B. (E-ring)
™Fix thread trimmer solenoid pin in
the center of shaft.
(See item 2 on page 21 for the
adjustment.)
Point
™Position of thread trimmer
solenoid : move thread trimmer
solenoid mas. asm. to the left and
right so that moving knife arm 4
comes in close contact with
moving knife roller arm 5when
the solenoid performs suction and
securely tighten 3.
Looper and thread release
function should not obstruct the
suction when the solenoid
performs suction.
3. Thread trimmer solenoid mas. asm.
Preparation
™Remove arm cover asm.
™Remove bed cover asm.
™Remove thread trimmer solenoid link B.
(See 2of the previous item.)
4. Moving knife base mas. asm.
Preparation
™Remove bed cover.
™Remove throat plate asm .
Disassembly
Remove E-ring of 1and raise frame.
Remove two setscrews of 2.
Bring feed dog of 3to its highest
position.
™Raising moving knfe base by
hand, lightly press moving knife
link A from upper side.
(Release coupling.)
Assembly
™Attach moving knife base to frame
while setting moving knife base to
moving knife link A.
™Temporarily tighten setscrews
2.
™Push moving knife base in the
direction of right front 45˚ and
securely tighten it.
™Tilt frame, set moving knife link
shaft A and enter E-ring 1.
Point
™When assembling, it is better to
raise by finger moving knife link
A from below.
1Moving knife link
shaft A E-ring
2Moving knife
base mas. asm.
setscrew
SM4040855SP
3Feed dog
3Thread trimmer solenoid
mas. asm. setscrew
SM5050855SN 1Thread trimmer solenoid pin setscrew
SM8050602TP
5Moving knife roller arm
4Moving knife arm
2Thread trimmer
solenoid link A

–15 –
[5] PRINTED CIRCUIT BOARD DIAGRAM (CONNECTOR LAYOUT)
(Caution) 1. CN Nos. in frame of MAIN circuit board denote connector Nos. in MAIN circuit board.
2. Portions enclosed with thick frame denote circuit boards.
3. Numerals outside of frame of MAIN circuit board denote number of lead wires.
Note : Convex portion of connectors, CN1, CN2 and CN3 should be placed up.
Controller
External thread
trimmer socket
External thread
trimmer
(Pedal SW)
Controller
socket
Bobbin winder SW
Thread trimmer
solenoid Lamp SW
Power transformer
(AC12V)
Power SW
Main motor
MP detection
circuit board
MAIN circuit
board
Lamp
CN11 Thread trimmer SW
circuit board
AC120V
Plug socket
3
3
2
33
22
2
2
2
2
CN8
CN7
CN1
5.6.7
CN5 CN6
CN4
CN2
CN1
3.4
CN1
1.2
CN3
Description MAIN circuit board Cord
Terminal Pin color
MP detection circuit CN6 1 Red
board 2 Brown
3 Black
Thread trimmer CN1 3 Gray
solenoid 4 Orange
Power input CN2 1 Yellow
2 Blue
Controller socket CN8 1 Yellow
2 White
Lamp CN4 1 White
2
Transformer CN1 1 Blue
Primary side (AC120V) 2 White
Secondary side CN3 1 Yellow
(AC12V) 2 Yellow
Description MAIN circuit board Cord
Terminal Pin color
Thread trimmer CN7 1 Orange
SW circuit board 2 Black
3 Brown
Bobbin winder SW CN5 1 Gray
2 Black
3 Purple
Motor CN1 5 Gray
6 Red
7 Black
Description Thread trimmer SW circuit board Cord
Terminal Pin color
Pedal SW CN11 1 Brown
2 Black
CN1 CN2 CN4 CN3
CN5 CN6 CN7 CN8
Connector insertion diagram
Convex portion

–16 –
General Mechanism
1. Height of needle bar bushing
™Set dimension from top surface of throat plate to
lower end face of needle bar bushing to 64.8
±0.1mm. (bushing : driving fit)
2. Height of needle bar
™Lower dead point of needle bar
™Align upper engraved line Aon needle bar 2with
lower end face of needle bar bushing 3.
™Perform adjustment with needle bar connection
setscrew.
General mechanism
1. Height of neddle bar bushing ...........................16
2. Height of needle bar.........................................16
3. Height of presser foot.......................................17
4. Height of feed dog............................................17
5. Feed timing ......................................................17
6. Needle-to-hook timing......................................17
7. Clearance between needle and hook .............. 18
8. Position of bobbin case positioning finger........18
9. Tension of thread take-up spring ..................... 18
10. Stroke of thread take-up spring
(absorbing amount of thread)...........................18
11. Bobbin thread tension ......................................19
12. Position of bobbin winder clutch ......................19
13. Adjustment of bobbin winder............................20
Automatic thread trimmer mechanism
1. Positioning of moving knife arm installing plate
(adjustment of position of moving knife) .......... 21
2. Installing position of thread trimmer solenoid
(moving amount of thread trimmer cam
contactor shaft) ................................................ 21
3. Thread trimmer cam timing
(needle-to-cam position) ..................................22
4. Position and protruding amount of looper
(left/right position and adjustment of movement)
.........................................................................23
5. Position of nut of wire setscrew
(adjustment of thread tension disk open/close)
.........................................................................23
[6] ADJUSTMENT OF COMPONENTS
Lower end face of needle bar
bushing
Top surface of throat plate
64.8±0.1 mm
Needle bar connection
setscrew
3
3
A

–17 –
3. Height of presser foot
™Adjust the height in the state that hand lifter lever
is raised.
™Clearance provided between top surface of throat
plate and lower face of presser foot is 7.0±0.5 mm.
™Perform adjustment with presser bar connection
setscrew.
4. Height of feed dog
™Set stitch dial to 2 and bring feed dog to its highest
position.
™See the height at top end of this side of feed dog.
™Bottom of tooth of feed dog should be aligned with
top surface of throat plate.
(Figure on the right side : protruding amount from
top surface of throat plate is 1.2±0.1 mm.)
™Perform adjustment with vertical feed shaft arm
1.
5. Feed timing
™Set stitch dial to the maximum.
™Lower feed dog in the normal feed operation and align it with top surface of throat plate.
™At this time, clearance provided between needle top and top surface of throat plate is 0±0.2 mm.
™Perform adjustment with feed cam setscrew.
6. Needle-to-hook timing
™Loosen three setscrews in hook.
™Align lower engraved line 1on needle bar with
bottom end face of needle bar bushing when needle
bar goes up from its lower dead point.
™Align blade point of hook with center line of needle,
check clearance between needle and hook, and
tighten setscrews.
Remove bobbin case positioning finger to improve
the work.
Throat plate
Presser foot
7.0±0.5 mm
Top surface of throat plate
1.2±0.1 mm
Feed cam setscrew
Needle (HA x 1 #14)
Top surface of throat plate
0±0.2 mm
Hook
1
1
1Vertical feed shaft arm
2Shaft arm setscrew

–18 –
7. Clearance between needle and hook
™Loosen three setscrews in hook.
™Align blade point of hook with center of needle.
™Adjust clearance provided between blade point of
hook and needle to 0.05 to 0.1 mm.
™Temporarily tighten setscrews, check the timing,
and securely tighten setscrews.
8. Position of bobbin case positioning finger
™ Loosen bobbin case positioning finger setscrew 1.
™Align right end of convex of bobbin case positioning
finger spring with right end of needle.
™Temporarily tighten setscrews, hold a clearance of
0.6 to 0.8 mm between inner hook and bobbin case
positioning finger, and securely tighten setscrew
2.
Bobbin case positioning finger should not come in
contact with hook.
9. Tension of thread take-up spring
™Pass needle thread up to thread tensioner thread guide 1.
™Lower presser foot and draw needle thread.
™Adjust tension of thread take-up spring to 0.127 to 0.157N when thread take-up spring starts lowering.
™For adjustment, loosen thread tensioner setscrew and turn thread tensioner 3.
™Turning clockwise = increasing tension of thread take-up spring 4.
10. Momentum of thread take-up spring (absorbing amount of thread)
™Pass needle thread up to thread take-up and lower
presser foot.
™Draw needle thread from start of motion of thread
take-up spring to end of its motion.
™Needle thread is absorbed when it is returned.
Absorbing amount : 10.5±0.5 mm
™Perform adjustment with thread take-up spring
adjusting plate 1.
0.05 to 0.1 mm
Needle (HA x 1 #14)
Blade point
1Bobbin case positioning
finger setscrew.
Top view
Bobbin case
positioning
finger
Needle
Front view
Needle
Bobbin case positioning
finger spring
0.6 to 0.8 mm
Align right end of
convex of bobbin case
positioning finger
spring with right end of
needle.
Setscrew 1Thread take-up spring
adjusting plate.
10.5±0.5 mm
2Thread tensioner
setscrew
1Thread tensioner
thread guide
3Thread tensioner
asm.
4Thread take-up spring
2
Needle thread