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  4. MC9900
  5. Service Manual

Janome MC9900 Service Manual

Other manuals for MC9900: Additional Service Manual

Summary of MC9900

  • Page 1

    Service manual & parts list mc9900

  • Page 2

    Index changing external parts face cover ...........................................................................................................................................1 belt cover ..............................................................................................................

  • Page 3: Changing External Parts (1)

    1 setscrews face cover changing external parts (1) face cover to remove: 1. Remove the setscrews (2 pcs.). Remove the face cover. To attach: 1. Follow the above procedure in reverse. Belt cover to remove: 1. Remove the cap and setscrew a. 2. Loosen the setscrews b and c. Remove the belt cover. To at...

  • Page 4: Changing External Parts (2)

    2 flange plate mark a spring mark a spring fig. 2 changing external parts (2) top cover to remove: 1. Raise the carrying handle and remove the setscrew a. 2. Open the top cover. Pull out the flange plate from the bobbin winder spindle (see fig. 2). 3. Remove the setscrew b and c. 3. Open the face co...

  • Page 5: Changing External Parts (3)

    3 setscrews changing external parts (3) base plate to remove: 1. Remove the setscrews (x 4). 2. Remove the base plate. To attach: 1. Follow the above procedure in reverse. Base plate fig. 1 rail cover setscrews setscrews base cover fig. 2 base cover to remove: 1. Slide the rail cover in the direcito...

  • Page 6: Changing External Parts (4)

    4 pin free arm cover changing external parts (4) bed cover to remove: 1. Remove the setscrews (x 2). 2. Remove the bed cover. To attach: 1. Follow the above procedure in reverse. Bed cover setscrew fig. 1 fig. 2 needle plate free arm cover free arm cover to remove: 1. Remove the needle and presser f...

  • Page 7: Changing External Parts (5)

    5 front right edge of the free arm cover guide fig. 3 setscrew free arm cover free arm cover free arm cover clearance changing external parts (5) fig. 4 fig. 5 hook fig. 6 fig. 7 6. Slide the free arm cover in the direction of arrow until there is no clearance between the free arm cover and the free...

  • Page 8: Changing External Parts (6)

    6 front cover to remove: 1. Remove the belt cover, top cover and base plate (see pages 1, 2 and 3). 2. Loosen the setscrews a, b, c, d and e (see fig. 1-5). 3. Push the rear cover through the holes f and g with a screwdriver to remove the hook of rear cover. 4. Remove the front cover. To attach: 1. ...

  • Page 9: Changing External Parts (7)

    7 changing external parts (7) fig. 1 rear cover setscrew a setscrew b fig. 2 setscrew c rear cover to remove: 1. Lower the presser foot. 2. Remove the belt cover, top cover and base cover (see pages 1, 2 and 3). 3. Loosen the setscrews a and b (see fig. 1). Remove the setscrews c (see fig. 2) 4. Pus...

  • Page 10

    8 replacing electronic components printed circuit board a to remove: 1. Remove the front cover (see page 6). 2. Grasp the connector directly with your fingers and pull. Do not pull the lead wire, as this may damage the contact sleeve inside the connector. Remove the setscrews. Remove the printed cir...

  • Page 11

    9 replacing electronic components printed circuit board f t o remove: 1. Remove the front cover (see page 6). 2. Disconnect the connector from the circuit board a (see page 8). 3. Remove the cs rings. 4. Remove the setscrews and the circuit board f. To attach: 1. Follow the above procedure in revers...

  • Page 12

    10 switching power supply unit to remove: 1. Remove the belt cover (see page 1). 2. Loosen the setscrew a. Remove the cord guide plate. (see fig. 1) 3. Disconnect the relay connector between the printed circuit board a and the switching power supply unit (see fig. 2). 4. Disconnect the power supply ...

  • Page 13

    11 driving motor to remove: 1. Remove the belt cover and the base plate (see pages 1 and 3). 2. Loosen the setscrew a and remove the cord guide plate (see fig. 1). 3. Disconnect the dc motor connector from the printed circuit board a (see page 8). 4. Remove the setscrews b, and the dc motor (see fig...

  • Page 14

    12 replacing electronic components thread tension unit to remove: 1. Remove the belt cover, top cover, base plate and front cover (see pages 1, 2, 3 and 6). 2. Disconnect the printed circuit board g3 (thread tension motor) connector and printed circuit board g1 (thread cut detecting sensor ) connect...

  • Page 15: Mechanical Adjustment

    13 ⇒ mechanical adjustment feed dog height when the foot pressure dial is at “5” and the presser foot a is lowered, the highest position of the feed dog should be 0.80 to 0.90 mm from the surface of the needle plate. Presser foot feed dog 0.85±0.05 mm surface of needle plate reverse stitch button st...

  • Page 16: Mechanical Adjustment

    14 ⇒ mechanical adjustment clearance between needle and tip of the rotary hook the clearance between the needle and the point of hook should be -0.1 to +0.05 mm. 1. Remove the top cover (see page 2). 2. Remove the presser foot pressure dial, presser foot, the needle plate and the bobbin holder. (see...

  • Page 17

    15 adjustment 2 1. Remove the base cover and bed cover (see page 3 and 4). 2. Loosen the setscrews a and b. Loosen the setscrew c just enough to move the hook base plate (see fig. 5). 3. Turn the handwheel toward you. Adjust the clearance between the needle and the tip of the rotary hook by moving t...

  • Page 18: Mechanical Adjustment

    16 mechanical adjustment backlash between hook drive gear and lower shaft gear the rotary play of the hook should be 0.8 mm or less when the tip of rotary hook is within the width of feed dog. 1. Remove the presser foot, the needle plate and the bobbin holder. (see page 4 and 5) * cover the needle p...

  • Page 19: Mechanical Adjustment

    17 ⇒ mechanical adjustment needle drop position when the straight stitch is selected, the needle should be positioned in the center of the needle plate hole. When the needle drop position is set at "0.0" and "9.0", the clearance between the side of the needle and the needle hole should be 0.2 mm or ...

  • Page 20: Mechanical Adjustment

    18 ⇒ mechanical adjustment hook timing the amount of ascending travel of the needle bar from its lowest position to the position (needle drop position 0.0) where the tip of the rotary hook exactly meets the right side of the needle should be 3.70 to 4.00 mm to adjust: 1. Attach the needle #14. 2. Tu...

  • Page 21: Mechanical Adjustment

    19 ⇒ 1. Attach the needle #14. 2. Turn the power switch on. Select straight stitch . Set the needle drop position at "0.0". * do not turn the switch off. 3. Remove the presser foot, the needle plate and the bobbin holder (see page 4 and 5). * cover the needle plate with the fabric to prevent damagin...

  • Page 22: Mechanical Adjustment

    20 ⇒ ⇒ upper shaft shield plate position when the machine is set for zigzag stitch, the needle should start to swing 7.2 to 8.2 mm above the surface of the needle plate. To check: 1. Attach the needle #14. 2. Remove the top cover (see page 2) 3. Turn the power switch on while pressing start/stop but...

  • Page 23: Mechanical Adjustment

    21 ⇒ mechanical adjustment upper thread tension the standard upper thread tension should be 59 to 67 grams when pulling the thread (white polyester thread size 50) at the speed of 110 mm/sec with the tension at "3.4" (be sure the presser foot is lowered). Pulling direction: (pulling speed 110 mm/sec...

  • Page 24: Mechanical Adjustment

    22 0.2 to 0.8 mm view a mechanical adjustment tension release mechanism when the presser foot is lowered, the thread tension discs will be closed and pull the thread. When the thread tension will be released, the tension disc will be opened and release the thread correctly. Thread tension gear conve...

  • Page 25: Mechanical Adjustment

    23 mechanical adjustment needle threader plate if the hook of the threader plate is damaged, change or adjust the part as follows: threader plate supporter (a) pin (b) hook groove to remove: 1 push down the needle threader knob and pull the needle threader plate (a) down to remove it (see fig. 1). T...

  • Page 26: Mechanical Adjustment

    24 mechanical adjustment thread drawing lever the standard height of the thread drawing lever from the surface of bobbin holder should be in the range of 5.5 to 6.0 mm. 1. Remove the presser foot, the needle plate and the bobbin holder. (see page 4-5) * you may use a fabric to prevent damaging the n...

  • Page 27: Mechanical Adjustment

    25 ⇒ mechanical adjustment buttonhole lever adjustment start/stop button reverse stitch button setscrew a buttonhole lever guide 1 turn the power switch on while pressing the start/stop button and the reverse stitch button to enter the factory setting mode. Press "bh sensor" key. 2. Attach the autom...

  • Page 28: Mechanical Adjustment

    26 presser bar lifter position the clearance between the presser foot and the surface of the needle plate should be 5.7 to 6.3 mm when the presser foot is raised. The presser foot (zigzag foot a) should be pararell to the slot of the feed dog teeth when attached. To adjust: 1. Turn the power switch ...

  • Page 29: Mechanical Adjustment

    27 embroidery foot height the distance between the embroidery foot and the surface of the needle plate should be in the range of 0.9 to 1.5 mm when the presser bar is at its lowest position. To adjust: 1. Remove the top cover (see page 2) 2. Remove the needle. Attach the embroidery foot (p). 3. Adju...

  • Page 30: Mechanical Adjustment

    28 ⇒ embroidery foot detecting sensor adjustment mechanical adjustment start/stop button reverse stitch button to adjust: adjust the presser foot height and embroidery foot height before this adjustment (see page 26 and 27). 1. Remove the top cover (see page 2). Remove the setscrews (see fig. 1). Re...

  • Page 31: Mechanical Adjustment

    29 ⇒ presser foot lifter detecting switch adjustment mechanical adjustment to adjust: 1. Remove the top cover (see page 2). 2. Turn the power switch on while pressing the start/ stop button and the reverse stitch button to enter the factory setting mode. Press "foot sen/feed dog" key. 3. Lower the p...

  • Page 32: Mechanical Adjustment

    30 ⇒ presser foot actuator arm bush mechanical adjustment knee lifter to adjust: 1. Remove the top cover (see page 2) 2. Remove the presser foot holder. 3. Lower the presser foot lifter. 4. Turn the handwheel toward you to lower the presser foot bar at its lowest position. 5. Loosen the nut. Adjust ...

  • Page 33: Mechanical Adjustment

    31 end of thread cutter plate slit 0.8 to 1.6 mm edge of moving cutter sensor plate setscrew thread cutter switch thread cutter base plate moving cutter mechanical adjustment thread cutter the distance between the end of thread cutter plate slit and the edge of moving cutter should be in the range o...

  • Page 34: Mechanical Adjustment

    32 ⇒ ⇒ remaining bobbin thread sensor 1. Prepare the empty bobbin (diameter: 8.4 mm) and the gauge bobbins (diameter: 12.5 mm and diameter: 18.9 mm). 2. Remove the presser foot and needle plate. (see page 4 and 5) * you may use a fabric to prevent damaging the needle plate. 3. Turn the power switch ...

  • Page 35: Mechanical Adjustment

    33 setscrews tp needle plate sensor fig. 1 needle plate base plate slide plate positioning plate fixed cutter spacer ◎ mark 11–11.5 mm rear side of the needle plate needle plate sensor knob needle plate micro switch actuator micro switch base plate setscrews tp fig. 2 fig. 3 mechanical adjustment ne...

  • Page 36

    34 ⇒ ⇒ 4. Turn the power switch on while pressing the start/ stop button and the reverse stitch button to enter the factory setting mode. Press "other sensor" key. 5. Be sure that "straight" indicates "l", and "zigzag" indicates "h" when the needle plate is attached. 6. Replace the needle plate with...

  • Page 37: Mechanical Adjustment

    35 the upper part thread amout is smaller than its lower part mechanical adjustment bobbin winder the amount of thread wound on the bobbin should be 16.5 to 19.5 mm in diameter. To adjust bobboin thread amount: 1. Loosen the setscrew a. Adjust the stopper position to determine the thread amount of b...

  • Page 38: Mechanical Adjustment

    36 ⇒ mechanical adjustment stretch stitch feed balance when the stretch pattern "8" is sewn 8 times with the stretch stitch balancing dial at the standard setting mark, the length of five of stretch patterns should be in the range of 33 to 39 mm. To check: 1. Attach the satin stitch foot (f). 2. Tur...

  • Page 39: Mechanical Adjustment

    37 ⇒ mechanical adjustment y-carriage play adjustment there should be no play in the direction of arrow a (see fig. 1). 1. Push down the lever to open the y-carriage. 2. Remove the cap under the embroidery unit (see fig. 2). 3. Move the x-carriage to the point where you can access the y fixing plate...

  • Page 40: Mechanical Adjustment

    38 to adjust: 1. Remove the foot holder. 2. Turn the power switch off. Attach the embroidery unit. Extend the carriage arm. 3. Attach the embroidery hoop and the template. 4. Turn the power switch on while pressing the start/stop button and the reverse stitch button to enter the factory setting mode...

  • Page 41: Mechanical Adjustment

    39 1. Turn the power switch off. Attach the embroidery hoop. (do not open the y-carriage.) 2. Attach the cloth guide to the embroidery carriage. 3. Turn the power switch on while pressing the start/ stop button and the reverse stitch button to enter the factory setting mode. Press "cloth guide" key....