Janome NH15 Troubleshooting guide

1
SERVICE MANUAL
&
MODEL: NH15
PARTS LIST

2
CONTENTS
WHAT TO DO WHEN ...................................................................................... 3-5
SERVICE ACCESS
FACE COVER ............................................................................................... 6
TOP COVER ................................................................................................. 6
BASE COVER............................................................................................... 7
REAR COVER .............................................................................................. 8
FRONT COVER ............................................................................................ 9
MECHANICAL ADJUSTMENT
NEEDLE THREAD TENSION .................................................................... 10
BOBBIN TENSION...................................................................................... 11
PRESSER BAR HEIGHT AND ALIGNMENT ............................................. 12
NEEDLE SWING ........................................................................................ 13
NEEDLE DROP POSITION ........................................................................ 14
CLEARANCE BETWEEN NEEDLE AND SHUTTLE............................. 15-16
FEED DOG HEIGHT................................................................................... 17
NEEDLE BAR HEIGHT............................................................................... 18
NEEDLE TIMING TO SHUTTLE ................................................................. 19
BUTTONHOLE FEED BALANCE ............................................................... 20
DISENGAGEMENT OF CAM FOLLOWER................................................. 21
MOTOR BELT TENSION............................................................................. 22
WIRING....................................................................................................... 23
PARTS LIST ............................................................................................... 24-41

3
CONDITION CAUSE HOW TO FIX REFERENCE
1. SKIPPING 1. NEEDLE IS NOT INSERTED INSERT THE NEEDLE PROPERLY.
STITCHES PROPERLY.
2. NEEDLE IS BENT OR WORN. CHANGE THE NEEDLE.
3. INCORRECTLY THREADED RETHREAD.
4. NEEDLE OR THREAD ARE USE THE RECOMMENDED
INAPPROPRIATE FOR THE SEWING NEEDLE AND THREAD.
FABRIC BEING SEWN.
5. SEWING ON STRETCH USE A #11 BLUE TIP NEEDLE.
FABRIC
6. INAPPROPRIATE NEEDLE SEE MECHANICAL P.18
BAR HEIGHT ADJUSTMENT
“NEEDLE BAR HEIGHT.”
7. INAPPROPRIATE NEEDLE SEE MECHANICAL P.19
TO HOOK TIMING ADJUSTMENT “NEEDLE
TIMING TO SHUTTLE.”
8. INAPPROPRIATE NEEDLE SEE MECHANICAL P.15,16
TO SHUTTLE CLEARANCE ADJUSTMENT “CLEARANCE
BETWEEN NEEDLE AND
SHUTTLE.”
2. FABRIC NOT 1. INCORRECT SEE MECHANICAL P.17
MOVING FEED DOG HEIGHT ADJUSTMENT “FEED DOG
HEIGHT.”
2. THREAD ON BOTTOM SIDE MAKE SURE TO BRING
OF FABRIC IS JAMMED UP. BOTH NEEDLE AND BOBBIN
THREADS UNDER THE FOOT
WHEN START SEWING.
3. FEED DOG TEETH ARE CHANGE THE FEED DOG.
WORN.
WHAT TO DO WHEN

4
CONDITION CAUSE HOW TO FIX REFERENCE
3. BREAKING 1. INITIAL SEWING SPEED IS START WITH MEDIUM SPEED.
UPPER TOO FAST.
THREAD 2. THREAD PATH IS USE THE PROPER THREAD
INCORRECT. PATH.
3. NEEDLE IS BENT OR DULL. REPLACE WITH A NEW NEEDLE.
4. UPPER THREAD TENSION IS ADJUST UPPER THREAD P.10
TOO STRONG. TENSION CORRECTLY.
5. NEEDLE SIZE IS USE APPROPRIATE NEEDLE
INAPPROPRIATE FOR AND THREAD FOR FABRIC
FABRIC. IN USE.
6. NEEDLE EYE IS WORN. CHANGE THE NEEDLE.
7. NEEDLE HOLE IN NEEDLE REPAIR THE HOLE OR
PLATE IS WORN OR BURRED. REPLACE THE NEEDLE PLATE.
4. BREAKING 1. INCORRECTLY THREADED THREAD BOBBIN CASE
BOBBIN BOBBIN CASE. CORRECTLY.
THREAD 2. TOO MUCH THREAD IS ADJUST THE POSITION OF
WOUND ON THE BOBBIN. STOPPER.
3. LINT IS STUCK INSIDE THE CLEAN THE HOOK RACE.
HOOK RACE.
4. THREAD QUALITY IS CHANGE TO A HIGH QUALITY
TOO LOW. SEWING THREAD.
5. THREAD IS JAMMING CLEAR OUT THE JAMMING
AROUND THE BOBBIN. THREAD.
6. BOBBIN THREAD TENSION IS ADJUST BOBBIN THREAD P.11
TOO STRONG. TENSION CORRECTLY.
5. NEEDLE 1. NEEDLE IS HITTING THE SEE MECHANICAL P.14
BREAKS NEEDLE PLATE. ADJUSTMENT “NEEDLE DROP.”
2. NEEDLE IS BENT OR WORN. CHANGE THE NEEDLE.
3. NEEDLE IS HITTING THE SEE MECHANICAL P.15, 16
SHUTTLE RACE. ADJUSTMENT “CLEARANCE
BETWEEN NEEDLE AND SHUTTLE”.
4. THE FABRIC MOVES WHILE SEE MECHANICAL P.13
THE NEEDLE IS PIERCING ADJUSTMENT “NEEDLE SWING”.
IT, OR THE NEEDLE ZIGZAGS
WHILE IN FABRIC.
5. FABRIC IS BEING PULLED TOO GUIDE THE FABRIC GENTLY
STRONGLY WHILE SEWING. WHILE SEWING.
WHAT TO DO WHEN

5
CONDITION CAUSE HOW TO FIX REFERENCE
6. NOISY 1. BACKLASH BETWEEN SEE MECHANICAL P.16
OPERATION SHUTTLE HOOK GEAR AND ADJUSTMENT “CLEARANCE
LOWER SHAFT GEAR IS TOO BETWEEN NEEDLE AND
GREAT. SHUTTLE (NO.2)”.
2. LOWER SHAFT GEAR IS ELIMINATE THE LOOSENESS.
LOOSE.
3. INAPPROPRIATE BELT SEE MECHANICAL P.24
TENSION. ADJUSTMENT “MOTOR BELT
TENSION”.
4. UPPER SHAFT GEAR IS LOOSE. ELIMINATE THE LOOSENESS.
5. NOT ENOUGH OIL. OIL ALL MOVING PARTS.
7. DEFORMATION 1. INAPPROPRIATE ZIGZAG SEE MECHANICAL P.13
PATTERN SYNCHRONIZATION. ADJUSTMENT “NEEDLE
SWING”.
2. INAPPROPRIATE SEE MECHANICAL P.23
DISENGAGEMENT OF CAM ADJUSTMENT
FOLLOWER. “DISENGAGEMENT OF CAM
FOLLOWER".
3. UPPER THREAD TENSION ADJUST UPPER THREAD P.10
IS TOO STRONG. TENSION CORRECTLY.
WHAT TO DO WHEN

6
FACE COVER
SETSCREW(B)
CAP(A)
SETSCREW(C)
THREAD GUIDE
SERVICE ACCESS
FACE COVER
TO REMOVE:
1. REMOVE THE FACE COVER BY REMOVING THE CAP (A) AND SETSCREW (B).
TO ATTACH:
2. FOLLOW THE ABOVE PROCEDURE IN REVERSE.
TOP COVER
TO REMOVE:
1. REMOVE THE SETSCREWS (C).
2. SLIDE THE CORNER OF THE TOP COVER SLIGHTLY IN THE DIRECTION OF ARROW.
BE CAREFUL THAT THE THREAD GUIDE SHOULD NOT INTERFERE WITH THE TOP
COVER WHEN REMOVING.
3. TAKE THE TOP COVER OUT.
TO ATTACH:
4. FOLLOW THE ABOVE PROCEDURE IN REVERSE.

7
(A)
BASE COVER
SERVICE ACCESS
BASE COVER
TO REMOVE:
1. LOOSEN THE SETSCREWS (A).
2. REMOVE THE BASE PLATE.
TO ATTACH:
3. MOUNT THE BASE PLATE AND SECURE IT WITH SETSCREWS.

8
(B)
(A)
(C)
(D)
(E)
(F)
(G)
(H) (I)
(J)
(C)
SERVICE ACCESS
REAR COVER
TO REMOVE:
1. REMOVE THE FACE COVER AND SETSCREW (A) (SEE PAGE 4).
2. OPEN THE SHUTTLE COVER AND REMOVE THE SETSCREWS (B), (C) AND (D).
3. REMOVE THE CAPS AND SETSCREWS (E), (F), (G),
4. REMOVE THE SETSCREWS (H) AND (I).
5. OPEN THE TOP COVER (SEE PAGE 5). LOOSEN THE SETSCREW (J).
6. REMOVE THE REAR COVER.
TO ATTACH:
7. MOUNT THE REAR COVER IN REVERSE PROCEDURE OF THE REMOVING.

9
(A)
(B)
(C)
(D)
(E)
(F)
(G)
(H)
SERVICE ACCESS
FRONT COVER
TO REMOVE:
1. REMOVE THE FACE COVER AND TOP COVER (SEE PAGE 4 AND 5).
2. LOOSEN THE SETSCREW (A).
3. REMOVE THE SETSCREW (B),
REMOVE THE REAR COVER (SEE PAGE 6).
LOOSEN THE SETSCREW (C), (E) AND (H). REMOVE THE SETSCREW (D).
4. OPEN THE SHUTTLE COVER. REMOVE THE SETSCREW (F).
5. REMOVE THE BASE COVER AND THE SETSCREW (G) (SEE PAGE 5).
TO ATTACH:
6. MOUNT THE FRONT COVER IN REVERSE PROCEDURE OF THE REMOVING.

10
MECHANICAL ADJUSTMENT
TOP TENSION
THE TOP TENSION SHOULD BE BETWEEN 65 AND 95G 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 “3”.
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.
WHITE POLYESTER THREAD SIZE 50
PULL THE THREAD AT THE SPEED OF 110 MM/
SEC IN THE DIRECTION OF ARROW
(A)
(B)