Janome 3160QOV User manual

SERVICE MANUAL
MODEL: 3160QOV
First Edition: 08 March 2019

INDEX
What to do when .............................................................................................................................. 1 - 3
Changing External Parts
Face Cover ............................................................................................................................................. 4
Free-arm Cover ...................................................................................................................................... 5
Front Cover ....................................................................................................................................... 6 - 7
RearF Cover ........................................................................................................................................... 8
Mechanical Adjustment
Presser Bar Height ................................................................................................................................. 9
Needle Drop Position ........................................................................................................................... 10
Adjustment of Hook Timing .................................................................................................................. 11
Adjustment of Needle Bar Height ......................................................................................................... 12
Clearance between Needle and Tip of Hook Rotary ............................................................................ 13
Feed Dog Height .................................................................................................................................. 14
Feed Dog Adjustment (Only for model 3160QDC) ............................................................................... 15
Top Tension .......................................................................................................................................... 16
Replacing the Electronic Components
Circuit Board-A connection .................................................................................................................. 17
Self-diagnostic Test ......................................................................................................................... 18-22
Circuit Board-A ................................................................................................................................ 23-24
Driving Motor ........................................................................................................................................ 25
Switching regulator Unit ....................................................................................................................... 26
Adjusting Buttonhole Lever Position ..................................................................................................... 27
Parts List ........................................................................................................................................ 28-41

1
Condition Cause How to fix Reference
1. Skipping
Stitches 1. Needle is not inserted properly.
2. Needle is bent or worn.
3. Incorrectly threaded.
4.Needle or thread are
inappropriate for the fabric being
sewn.
5. Sewing on stretch fabric.
6. Inappropriate needle bar height.
7. Inappropriate needle to hook
timing.
8. Inappropriate needle to hook
clearance.
Insert the needle properly.
Change the needle.
Rethread.
Use the recommended sewing needle
and thread.
Use a HA x #11 blue tip needle.
See mechanical adjustment “Needle bar
height”.
See mechanical adjustment “Adjustment
of hook timing”.
See mechanical adjustment “Clearance
between needle and tip of the rotary
hook”.
P. 12
P. 11
P. 13
2. Fabric not
moving 1.Incorrect feed dog height.
2.Feed dog is in down position.
3.Thread on bottom side of fabric is
jammed up.
4.Feed dog teeth are worn.
Adjust the presser bar level to make the
pressure stronger.See mechanical
adjustment “Feed dog height”.
Raise the feed dog.
Make sure to bring both needle and
bobbin threads under the foot when
start sewing.
Change the feed dog.
P. 14
What to do when

2
Condition Cause How to Fix Reference
3. Breaking
upper thread. 1.Initial sewing speed is too fast.
2.Thread path is incorrect.
3. Needle is bent or dull.
4.Top tension is too strong.
5.Needle size is inappropriate for
fabric.
6.Needle eye is worn.
7. Needle hole in needle plate is
worn or burred.
Start with medium speed.
Use the proper thread path.
Replace with a new needle.
Adjust top tension correctly.
Use appropriate needle for fabric and
thread in use.
Change the needle.
Repair the hole or replace the needle
plate.
4. Breaking
bobbin thread. 1. Bobbin holder is incorrectly threaded.
2. Too much thread is wound on
the bobbin.
3. Lint is stuck inside the bobbin
holder.
4. Thread quality is too low.
5. Thread is jamming around the
bobbin holder.
Set the bobbin thread correctly.
Adjust the position of bobbin winder
stopper.
Clean the bobbin holder.
Change to a high quality sewing thread.
Clear out the jamming thread.
5. Needle
breakes 1. Needle is hitting the needle plate.
2. Needle is bent or worn.
3. Needle is hitting the hook.
4. Fabric is being pulled too strongly
while sewing.
See mechanical adjustment “Needle
drop position”.
Change the needle.
See mechanical adjustment “Clearance
between needle and tiip of the rotary
hook”.
Guide the fabric gently while sewing.
P. 10
P. 13

3
Condition Cause How to fix Reference
6. Noisy
operation 1.Backlash between hook gear and lower shaft gear is too great.
2. Lower shaft gear is loose.
3. Inappropriatte belt tension.
4. Not enough oil.
5. Upper shaft gear is loose.
Eliminate the backlash.
Eliminate the looseness.
See part removal and replacement
“driving motor (DC motor)”.
Oil all moving parts.
Eliminate the looseness.
P. 25
7. Deformation
pattern 1. Inappropriate feed balance.
2.Top tension is too strong.
Adjust the feed balancing screw.
See mechanical adjustment
“Top tension”. P. 16

4
Changing External Parts
Face cover
To remove:
1. Loosen the setscrew qand lift the face cover to disengage the rib on the inside.Remove the face cover w.
To attach:
2. Follow the above procedures in reverse.
q
w

5
Free-arm cover
To remove:
1. Loosen the setscrew qand w. Move the free-arm cover to the left.Remove the free-arm cover.
To attach:
Follow the above procedures in reverse.
Changing External Parts
q
w
e

6
Changing External Parts
Front cover (1)
To remove:
1. Remove the face cover and free-arm cover (See page 4 and 5).
2. Remove the setscrews (A) q(2 pcs.).
3. Remove the setscrews (B) w(5 pcs.), back cover e.
4. Remove the setscrews (C) r(2 pcs.).
5. Disconnect all the connectors from the circuit board A.
NOTE:
Do not disconnect the connectors by pulling on cord.
To disconnect, grasp the connector, not the cord.
To attach:
6. Follow the above procedures in reverse.
qw
ww
rr
e

7
Changing External Parts
Front cover (2)
4. Disengage the front cover and rear cover hooks.
5. Remove the front cover.
To attach:
Follow the above procedures in reverse.

8
Changing External Parts
Rear cover
To remove:
1. Remove the face cover and free-arm cover (See page 4 and 5).
2. Remove the setscrews (A) q(4 pcs.).
3. Remove the setscrews (B) w(5 pcs.) and back cover.
4. Remove the setscrews (C) e(2 pcs.). Remove the rear cover.
To attach:
5. Follow the above procedures in reverse.
q
q
w
w
e
Back cover
Rear cover

9
６.０mm
Mechanical Adjustment
Presser bar height
The distance between the bottom of the presser foot in up position and the needle plate should be 6.0 mm.
1. Remove the face plate and needle.
2. Lower the feed dog below the needle plate. Place a block 6 mm thick under the presser foot and lower the
presser foot lifter w.
3. Loosen the setscrew q. Raise the presser foot lifter and tighten the setscrew qfirmly.
Attach the needle and face plate.
NOTE:
Make sure that the presser foot should be parallel to the feed dog slots e in the needle plate.
q
e
Presser foot should be
parallel to the feed dog slots.
w

10
0.2 mm
or more
0.2 mm
or more
Ａ=Ｂ
Mechanical Adjustment
Needle drop position
Set the stitch pattern to “ ”. The standard needle drop position should be at center of the needle plate hole q.
Select zigzag stitch “ ”, and set the stitch width at “5.0”.The clearance between the needle and the edge of
the needle hole in the needle plate should be at least 0.2 mm on either side.If not, adjust as follows:
1. Turn the power switch off.Remove the face cover. (See page 4.)
2. Loosen the hexagonal socket screw 3 x 4 w. Adjust the needle drop position by turning the eccentric pin e.
The direction of eccentric pin should be as shown in Fig. 1.
3. Attach the face cover.
NOTE:
Check the hook timing after this adjustment.
q
Fig. 1

11
The amount of ascending travel of the needle bar from its lowest position to the position ( ) where the tip of
the rotary hook exactly meets the right side of the needle should be 3.25 to 3.55 mm.
1. Remove the needle plate and bobbin holder.
2. Turn the power switch on.
3. Select the pattern (left position). Set the zigzag width at 0.
4. Remove the free-arm cover.
Turn the handwheel toward you to lower the needle at its lowest position.
5. Loosen the hexagonal socket screw w(2 pcs.).
6. Move the needle bar 3.4 mm from the lowest position.
7. Turn the lower shaft gear until the tip of hook meets the right side of the needle while holding the handwheel.
8. Tighten the hexagonal socket screw w(2 pcs.).
9. Attach the free-arm cover, bobbin holder and needle plate.
Mechanical Adjustment
Adjustment of hook timing
w
Needle plate
Bobbin holder
w
Lower shaft gear
Left position ( )
(#14)
Tip of hook meets the
right side of the needle
Lowest needle position
3.25 – 3.55mm

12
Before proceeding with this adjustment, check the hook timing (refer to page 11). The distance between the
upper edge of the needle eye and the tip of the hook should be in the range of 1.6 to 2.0 mm when the tip of the
hook timing meets right side of the needle in the left needle position ( ) as the needle ascends from its lowest
position.
1. Remove the needle plate, bobbin holder and face plate.
2. Turn the power switch on.
3. Select the pattern (left position). Set the zigzag width at 0.
4. Turn the handwheel toward you until the tip of hook meets the right side of the needle.
5. Loosen the hexagonal socket screw q.
6. Move the needle bar to adjust the needle bar height, and tighten the hexagonal socket screw q.
Be careful not to turn the needle bar.
7. Attach the bobbin holder, needle plate and face cover.
Mechanical Adjustment
Adjustment of needle bar height
1.6 – 2.0 mm
Needle plate
Bobbin holder
Hexagonal socket screw
Needle setting groove
Upper edge of needle hole
Hook race (unit)
Hook race
Tip of hook meets the right side of the needle
Left position ( )
(#14)

13
Adjustment procedure:
1. Remove the needle plate and bobbin holder.Attach the master needle.Turn the power switch on and set the
zigzag width at maximum.
2. Remove the face cover.
3. Loosen the setscrew A (2 pcs.).
4. Turn the handwheel toward you. Adjust the clearance between the needle and the tip of the rotarty hook, by
moving the hook base plate up or down, to within –0.1 to +0.05 mm at the left and right needle position.
5. Tighten the setscrew A (2 pcs.).
6. Attach the face cover. Remove the master needle.Attach the bobbin holder and needle pate.
7. Check the clearance between the needle and the edge of the needle hole in the needle plate (see page 10).
* The clearance between the needle and the point of hook should be –0.1 to +0.05 mm.
Clearance between needle and tip of the rotary hook
Mechanical Adjustment
Tip of hook
–0.1 to +0.05 mm
Needle plate
Bobbin holder
Needle bar supporter
adjusting plate Hexagonal socket screw (A)

14
The highest position of the feed dog should be between 0.80 and 0.90 mm from the surface of the needle plate.
1. Lower the presser foot and turn the power switch on.
2. Turn the handwheel toward you to set the feed dog at the highest position.
3. Remove the free-arm cover.
4. Loosen the setscrew (A) qand nut w.
5. Adjust the feed dog height by turning the adjusting screw e. The highest position of the feed dog should be
between 0.80 and 0.90 from the surface of the needle plate.
6. Tighten the nut wand setscrew (A) q.
7. Attach the free-arm cover.
Feed dog height
Mechanical Adjustment
AB
e
w
q
q
Presser foot
Feed dog
0.80 – 0.90mm
Surface of the needle plate

15
1. Use a hexagonal socket screw (4 x 6).
Insert the screw to the hole B. Tighten the hexagonal socket screw as far as it goes.
2. Loosen the setscrew C.(left screw)
3. Turn hexagonal socket screw to adjust the feed dog (should be parallel to the surface of the needle plate).
4. Tighten the setscrew C.(left screw)
5. Loosen the hexagonal socket screw and remove it.
The highest position of the feed dog should be parallel to the surface of the needle plate.
If not, adjust as follows.
Feed dog adjustment (Only for model 3160QDC)
Mechanical Adjustment
Setscrew C
Setscrew C
(left screw)
Hexagonal socket scrw 4 x 6
Hole B

16
Mechanical Adjustment
Top tension
The top tension should be between 65 and 80g when pulling the thread up in the direction of C.
* Use polyester sewing thread #50 (White).
* If it is not within the above limit, adjust as follows.
1. Set the tension dial “Auto”.
2. Remove the cover.
3. Lower the presser foot.
• If the top tension is too loose, turn the lead screw in the direction (A).
• If the top tension is too tight, turn the lead screw in the direction (B).
4. Check the top tension and attach the cover.
q
White polyester thread size 50
Pull the thread at the speed of 110
mm/sec in the direction of arrow
Cover

17
Circuit board-A Connection
NOTE:
Do not disconnect the connectors by pulling on cord.
To disconnect, grasp the connector, not the cord.
Replacing the Electronic Components
t
i
o
!0
!1
!2!3
!4 Printed circuit board A
Printed circuit board F
Printed circuit board L
qPrinted circuit board P (Black)
wFeed motor (White)
eThread cutter motor
(3160QDC exclusive) (White)
rBobbin winding switch (Blue)
tPower switch (White)
yZigzag width motor (Green)
uSolenoid
(3160QDC exclusive) (Black)
iPrinted circuit board F (White)
oPrinted circuit board L (White)
!0 Program (Red)
!1 Buttonhole sensor
program (Red)
!2 Presser foot lifter switch
(Green)
!3 DC motor (White)
!4 Controller (Black)
q
w
e
r
yu

18
To enter self-diagnostic mode:
Preparation:
1.Turn the power switch off.
2. Move the bobbin winder spindle to the left.
3. Raise the feed dog.
4. Set the speed control lever to the left.
5. Remove the presser foot and raise the presser foot lifter.
6.Turn the hand wheel toward you to raise the needle to its highest position.
Notes:
• Be careful: the sewing machine may start running in its own while in test mode.
• Turn off the power switch before replacing any parts.
• Repeat the diagnostic test until the problem has been resolved.
•You can skip steps in the diagnostic procedure and go directly to the test you want to perform.
(Enter self-diagnostic mode, then select the step number of the diagnostic test you require by
pressing the start/stop button)
To begin:
Turn on the switch, if any of the following problems occur, take the recommended actions in the order
they are shown.
1.The machine does not respond when the power switch is turned on:
• Check each connector connection
• Replace the machine socket
• Replace the Switching regulator.
• Replace the A-board
2.The sewing machine lamp does not light up:
• Replace the light bulb
• Replace the A-board
Self-diagnostic Test
Turn the power switch on
while simultaneously
pressing needle up/down
button and the locking
stitch button.
The LCD display will
indicate “01”. Press the start/stop button to enter the self-diagnostic mode.