Brother DB2-DD7100 Service Manual Download Page 106

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16. AUTO BOBBIN CHANGER

SL-710A

16. AUTO BOBBIN CHANGER

DANGER

Wait at least 10 minutes after turning off the power switch and disconnecting the power cord from the wall outlet
before opening the face plate of the control box. Touching areas where high voltages are present can result in
severe injury.

16-1. Timing

Obtain the bobbin changer signal from the CN6 connector
on the control circuit board.
•

When the lower thread amount is detected, a "L"
signal is output from pin (3) of CN6 for 500 ms.

•

The motor will not operate while a "L" signal is being
output from pin (2) of CN6.

16-2. Connector

The following bobbin changer connector is provided.

Part name

Part code

Bobbin changer connector
assembly

J03136-001

Note:

If purchasing the connector as a single part from
the manufacturer, specify the following number.

Manufacturer

MOLEX

Connector No.

51103-400

Connector terminal

50351-8100

16-3.Binding the cord

Pass the bobbin changer cord (1) under the control circuit
board and secure it using a cable tie (2).

1872M

<CN16>

(1)

(2)

1876M

1873M

1874M

1875M

Start prevention switch

Photocoupler

(1) DC5V

(2) Input from bobbin changer

(3) Output to bobbin changer

(4) SoV

+5V

SoV

Summary of Contents for DB2-DD7100

Page 1: ...SL 710A DB2 DD7100A DB2 DD7100 Please read this manual before making any adjustments SINGLE NEEDLE DIRECT DRIVE STRAIGHT LOCK STITCHER WITH THREAD TRIMMER SERVICE MANUAL ...

Page 2: ...ccidents and injury to yourself or other people The meanings of these indications and symbols are given below Indications D AN G E R The instructions which follow this term indicate situations where failure to follow the instructions will almost certainly result in death or severe injury CAUTION The instructions which follow this term indicate situations where failure to follow the instructions co...

Page 3: ...tlet Lightning may cause problems with correct operation Installation Machine installation should only be carried out by a qualified technician Contact your Brother dealer or a qualified electrician for any electrical work that mayneed to be done The sewing machine weighs more than 36 kg The installation should be carried out by two or more people Do not connect the power cord until installation i...

Page 4: ...ition If onlyone hand is used the weightof themachineheadmaycause your handtoslip andyourhandmaygetcaught Be sure to wear protective goggles and gloves when handling the lubricating oil so that no oil gets into your eyes or onto your skin otherwise inflammation can result Furthermore do not drink the oil under any circumstances as they can cause vomiting and diarrhea Keep the oil out of the reach ...

Page 5: ... symbol There is a ground symbol which is shown on the control box in the position shown in the illustration If other equipment needs to be grounded connect the ground wire to the screw which is next to this ground symbol If the ground connection is not secure you run a high risk of receiving a serious shock and problems with correct operation may also occur Finger guard 0766M 2 1 Thread take up c...

Page 6: ...rimmer cam 27 5 24 Stitch length dial 28 5 25 Reverse stitching lever and feed regulator 28 6 ASSEMBLY 29 6 1 Stitch length dial reverse stitching lever and feed regulator mechanism 29 6 2 Rotary hook shaft thread trimmer cam and gear 31 6 3 Plunger 31 6 4 Lower shaft lower shaft gear and feed regulator set 32 6 5 Timing belt motor and pulley 34 6 6 Knee lifter lever mechanism 36 6 7 Needle bar an...

Page 7: ... flowchart 82 12 3 Parameters 83 12 4 Memory switch setting flowchart 86 12 5 Memory switches 87 13 TREADLE UNIT ASSEMBLY 90 13 1 Types 90 13 2 Standard setting values 91 13 3 Setting method for standard depression strokes 92 14 STANDING OPERATION PEDAL 96 14 1 Installing the foot plug 96 14 2 Connectors 97 15 Puller commercially available 98 15 1 Timing 98 15 2 Connector 98 15 3 Binding the cord ...

Page 8: ... stroke 29 mm 31 mm 35 mm Thread take up stroke 57 4 mm 61 mm Feed dog 4 row 3 row 3 row Long stitch Feed dog height 0 8 mm 1 2 mm Presser bar lifter 6 mm Knee lifter 13 mm Presser foot height Automatic presser lifter 10 mm Presser foot pressure 10 40N 40 79 N 57 98 N Bed size 476 X 178 mm Arm pocket size 266 5 X 134 5 mm Needle DB X 1 NS 9 11 22 Rotary hook For light weight materials For medium w...

Page 9: ...1 SPECIFICATIONS SL 710A 2 Operation panel Operation panel Part code B 40 J80627 001 B 100 J80629 001 ...

Page 10: ...ls to new synthetic fabric specifications or if using the machine with standard specifications but with the rotary hook replaced by the rotary hook RP lubrication free rotary hook please use the following parts S44338 901 Rotary hook box assembly S35786 001 Cap screw When using the rotary hook RP lubrication free rotary hook set the sewing speed to 4 000 rpm or less Table parts Part name Part code...

Page 11: ...be carried by the arm by two people as shown in the illustration Do not hold the machine by the machine pulley Tilting back the machine head While pulling the bottom rear of the bed toward you with your left hand push the top right of the arm body with your rigth hand to tilt back the machine head Be careful not to get your left hand caught between the bottom of the bed and the table Returning the...

Page 12: ... and rotary hook mechanism 1627M 8 Lower shaft gear 7 Lower shaft 3 Joint 4 Timing pulley U 2 Rotor 1 Pulley 6 Timing pulley D 5 Timing belt 9 Gear 10 Rotary hook shaft assy 11 Rotary hook 1626M 5 Needle take up lever 4 Thread take up crank 3 Upper shaft 2 Rotor 1 Pulley 7 Slide block 8 Needle bar 1 2 6 Needle bar clamp The needle bar is guided by the needle bar bush U 1 and needle bar bush D 2 ...

Page 13: ...nt of feed bar Horizontal movement of feed bar 1629M 1628M 1 Pulley 1 Pulley 3 Level feed eccentric wheel 4 Level feed connecting rod 5 Feed regulator assy 6 Feed 7 Feed rocker bracket arm 8 Feed bar 2 Lower shaft 2 Lower shaft 4 Feed bar 3 F lifting eccentric wheel assy ...

Page 14: ...and feed rocker arm change from normal feed to reverse feed Operation occurs in the same way as described above even when the reverse stitching lever 1 is lowered 1632M 1631M Normal feed Reverse feed 4 Shaft 1 Actuator 2 Quick reverse solenoid 3 Solenoid lever 5 Handle shaft arm 6 Connecting rod 7 Stud arm 9 F regulator connecting rod S 13 Feed rocker shaft 12 Feed rocker arm 10 Feed regulator ass...

Page 15: ... 2 will rise as far as the upper reference line Refer to page 59 for details on the lubrication method 1 The lubricating oil that is poured into the oil filler hole 1 is stored in the oil tank 3 2 The lubricating oil in the oil tank 3 is drawn up by the plunger pump 4 3 The lubricating oil in the sub tank 5 is transferred to parts such as the thread take up lever and needle bar by wicks The rotary...

Page 16: ...stored in the oil tank 3 2 The lubricating oil in the oil tank 3 is drawn up by the plunger pump 4 3 The lubricating oil that is drawn up by the plunger pump 4 is transferred to parts such as the thread take up lever and needle bar by oil tubes and wicks The rotary hook lubrication amount can be adjusted using the adjusting screw 6 Refer to page 73 2 1 6 4 6 4 3 1638M 1635M 1634M 1637M Used oil Up...

Page 17: ...otary hook 1 When the thread trimmer signal is received 2 Thread trimmer holder action 1639M 1 Solenoid plunger 2 Solenoid lever 3 Thread trimmer cam lever shaft 4 Roller Moves over thread trimmer cam 1 1 1640M 1 Thread trimmer cam 2 Roller 3 Roller block 4 Forked shaft 5 Thread trimmer lever 6 Thread trimmer connecting rod 7 Thread trimmer holder 8 Movable knife ...

Page 18: ...fe to a position where it will not touch the needle 1642M 1641M 1 Thread trimmer lever 1 Spring 2 Thread trimmer lever 3 Thread trimmer holder 3 Solenoid lever 2 Forked shaft 4 Solenoid plunger 2 Thread trimmer connecting rod 1 Thread trimmer lever 4 Movable knife 3 Roller block 4 Roller 1 Thread trimmer cam 2 Return pin 3 Roller block 4 Forked shaft 5 Thread trimmer lever 6 Thread trimmer connect...

Page 19: ...he separation of the upper and lower threads by the movable knife and it may result in thread trimming errors 4 The upper and lower threads caught by the movable knife in 3 above are gradually spread by the knife and lower thread finger and cut by the fixed knife tip The thread take up lever has now approached the top of its stroke When the knife is spreading the thread the tension release relieve...

Page 20: ...ver 1 Thread trimmer solenoid 6 Tension release stud 5 Tension release plate 4 Tension release wire Disc presser Tension release stud Pin 4 Tension release wire 2 Bolt When raising the presser foot using a knee lifter or knee switch Discs 2 Presser bar lifter lever 1 Knee lifter connecting rod 4 Tension release stud 3 Tension release plate 1649M 1652M 1653M 1651M 1650M Seen from underneath When a ...

Page 21: ... wiper rod 3 Thread wiper crank assy 4 Thread wiper 1654M When knee switch is pressed 8 Knee lifter lever 9 Knee lifter connecting rod 10 Presser bar lifter lever 11 Guide bracket 6 Knee lifter lever D 5 Presser foot lifting rod 13 Presser foot 12 Presser bar 1 Presser foot solenoid 2 Presser bar lifting lever 5 Presser foot lifting rod 4 Presser foot lifting plate 3 Presser foot lifting shaft 165...

Page 22: ...s out The lower thread is detected after the thread is trimmed and the amount of lower thread remaining is displayed on the operation panel When a thread trimming signal is input Potentiolever Shaft of pin driving solenoid Driving lever Slider Detect pin 2 Driving lever 3 Slider 4 Detect pin Bobbin case 1 Shaft of pin driving solenoid Amount of lower thread remaining Remaining amount setting value...

Page 23: ...d when tilting it back or returning it to its original position If only one hand is used the weight of the machine head may cause your hand to slit and your hand may get caught Be sure to wear protective goggles and gloves when handling the lubricating oil so that no oil gets into your eyes or onto your skin otherwise inflammation can result Furthermore do not drink the oil under any circumstances...

Page 24: ...tor 2 Synchronizer connector 3 Lower thread detector connector 4 Machine connector 6 Motor connector 5 Solenoid type presser lifter connector 7 Pins Machine connector 1663M 1662M 4 Studs 2 pcs 1 Shoulder screw 6 Presser foot lifting rod 5 Shoulder screw 2 Bolts 3 pcs 3 Presser lifter solenoid assy 1664M 1 Screws 2 pcs 2 Lower thread detector 1665M ...

Page 25: ...ver 7 Screws 6 pcs 10 Face plate 11 Screw 14 Operation panel 15 Panel support brackets 2 pcs 4 Arm cover 3 Screws 4 pcs 13 Set screws 2 pcs Loosen 9 Screws 3 pcs 2 Bobbin winder tension assy 5 Screws 2 pcs Loosen 6 Cords 2 pcs 8 Rear cover 1 Set screw Loosen DD7100 1666M 1667M ...

Page 26: ...l out from machine head 7 Screw 2 pcs Loosen 1 Screw Loosen 2 Set screw Loosen 4 Tension release wire 3 Nuts 2 pcs 9 Thread trimmer solenoid 6 Ground wire 5 Screw 8 Screw DD7100A 710A only 11 Retaining ring E 14 Washer 10 Set screw Loosen 16 Spring 13 Cushion 12 Thread trimmer cam lever shaft Pull out 18 Rubber cushion 17 Collar 15 Thread trimmer cam lever assy 1669M 1671M 1670M 1668M ...

Page 27: ...bes 11 Screws 2 pcs 12 Sub tank 1 Screw Lubricating oil Lubricating oil 4 Screws 2 pcs 5 Oil tank 1 Place a dish under the lubricating oil outlet and then remove the screw and drain the lubricating oil 2 Securely tighten the screw into the lubricating oil outlet While holding a pan under the gear box loosen the eight screws The oil inside the gear box will start flowing out from the gear box when ...

Page 28: ...4 Screws 2 pcs 5 Oil tank 3 4 1675M While holding a pan under the gear box loosen the eight screws The oil inside the gear box will start flowing out from the gear box when you start to loosen the eight screws 1 Place a dish under the lubricating oil outlet and then remove the screw and drain the lubricating oil 2 Securely tighten the screw into the lubricating oil outlet DD7100 7 Knee lifter arm ...

Page 29: ...e 1 Set screw 3 Screw 4 Finger guard 5 Presser hoot Presser foot with integrated finger guard 1679M 1678M 1 Set screw Loosen 4 Arm thread guide 2 Pre tension assy 3 Screw 6 Thread tension bracket assy 7 Pin 8 Tension release stud 5 Set screw Loosen 10 Thread guide D 9 Thread guide 1680M 1 Screws 2 pcs 2 Needle plate 6 Screw 7 Ruler plate 5 Feed dog 4 Screws 2 pcs 3 Slide plate 1681M ...

Page 30: ...tion bracket 7 Washer 8 Lower thread finger 6 Screw 1 Screw 13 Movable knife 12 Screws 2 pcs Pull the movable knife holder in the direction of the arrow so that the two pan screws can be seen from the needle plate side 1682M 1683M 6 Set screws 2 pcs Loosen 7 Feed bracket assy Separate 5 Oil cap 3 Set screws 2 pcs Loosen 2 Feed lifting rock bracket stud with wick 4 Feed lifting eccentric wheel assy...

Page 31: ...k 16 Retaining ring E 15 Shaft Slide to the right 13 Spring 12 Washer 11 Retaining ring E 17 Shaft Pull toward the outside 19 Tension release plate 18 Washer 14 Set screw Loosen 1686M 1688M 1687M 1 Shoulder screw 3 Spring 2 Knee lifter connecting rod D slide 4 Shoulder screw 7 Lever shaft D 5 Presser bar lifter lever assy Remove in the direction of the arrow 6 Retaining ring E 8 Knee lifter lever ...

Page 32: ...fter removing the motor 2 remove the screws 1 3 Needle bar 8 Rubber cap 6 Set screw Loosen 5 Slide block 10 Crank 12 Thread take up assy 7 Needle bar bush U 4 Needle bar clamp 2 Screw Loosen 11 Set screws 2 pcs Loosen 9 Set screws 3 pcs Loosen 1 Rubber cap 1691M 2 1 A A 1694M 3 Screws 3 pcs 2 Pulley 1 Set screws 2 pcs Loosen 4 Set screws Loosen two screws at motor side 5 Motor and connectors Note ...

Page 33: ...the fan and flange do not need to be removed 4 Flange DD7100 only 1697M 10 Rubber cap 13 Feed regulator shaft L 14 Washer 11 Set screws 2 pcs Loosen 12 Feed regulator support shaft 7 Eccentric pin 9 Stud arm 6 Set screw Loosen 5 Spring 1 Bolt 4 Cover stud 3 Washer 2 Spring washer 15 Feed regulator Only the top can be removed 8 Set screws 2 pcs Loosen Note After removing the spring reinstall the co...

Page 34: ...et screw 2 pcs Loosen 8 Lower shaft gear 2 Set screw 2 pcs Loosen 3 Set screw 2 pcs Loosen 7 Feed regulator set 5 Spacer 2 pcs 4 Set screw 2 pcs 4 Set screw 4 pcs Loosen DD7100 1698M 1699M 1700M 8 Rotary hook shaft Pull out 10 Thread trimmer cam 9 Gear 7 Set screw 2 pcs Loosen 5 Spacers 2 pcs 6 Set screw 2 pcs Loosen 4 Set screws 2 pcs 3 Plunger 2 Spring 1 Cap screw ...

Page 35: ...ength dial counterclockwise again so that the stopper goes past the positioning pin 3 Positioning pin Push with a screwdriver or similar 1 Spring Remove from groove 7 Screw 2 pcs 6 Screw with washer and collar 3 Reverse lever plate 11 Bolt Loosen 9 Washer 2 Screw 15 Feed regulator 14 Set screws 2 pcs Loosen 8 Spacer 4 Reverse stitching lever 5 Spring With retaining ring E 10 Bolt Loosen 13 Solenoi...

Page 36: ...to your skin otherwise inflammation can result Furthermore do not drink the oil under any circumstances as they can cause vomiting and diarrhea Keep the oil out of the reach of children Use only the proper replacement parts as specified by Brother If any safety devices have been removed be absolutely sure to re install them to their original positions and check that they operate correctly before u...

Page 37: ... 710A Hook the end of the spring onto the inside of the screw 15 and under surface D as shown in figure B DD7100 Hook the end of the spring onto the inside of the screw 15 and under the stopper 17 as shown in figure C 9 Insert the reverse stitching lever 18 10 Set the reverse lever plate 19 so that it is facing as shown in the illustration and while inserting it into the groove in the reverse stit...

Page 38: ...the thread trimmer cam 2 and then tighten the set screws 5 two places 4 Push the rotary hook shaft 1 16 25 mm to the left of the edge of the bush 6 and then tighten the two set screws 7 and the two set screws 8 Align the screw stops of the rotary hook shaft 1 with the set screw above the set screws 7 and 8 Check that the rotary hook shaft 1 turns smoothly with no play in the axial left right direc...

Page 39: ...th the blade of the lower shaft gear 2 In this condition align the screw stops on the lower shaft 1 and then tighten the lower set screws 7 4 Tighten the upper set screws 7 5 Tighten the two set screws 8 At this time align the screw stops of the lower shaft 1 with the lower set screws 8 6 For the DD7100A and 710A insert the two spacers 9 into the screw holes in timing pulley D 4 7 While pushing th...

Page 40: ...rew stop is facing toward the front 12 Insert feed regulator shaft L 18 into the gear box 17 so that it protrudes about 2 3 mm from the inside edge and so that the screw stop is facing toward the front and then install the washer 19 13 Push back the feed regulator 13 so that it goes into the gear box 17 and then insert feed regulator shaft L 18 and the feed regulator support shaft 16 into the hole...

Page 41: ...and pulley 1 Insert the timing belt 1 through the motor mounting hole and place it onto timing pulley U 2 2 Install the flange 3 and the fan 4 to timing pulley U 2 with the three screws 5 For DD7100A 710A This step is not required 3 First pass the connector 7 of the motor 6 into the arm and then insert the motor 6 into the arm as far as it will go 4 Align the screw holes 8 in the arm with the scre...

Page 42: ...screw stop of the rotor 13 should be aligned with the set screw 15 that is at the rear relative to the turning direction of the pulley 14 8 Tilt back the machine head 9 Check that the timing belt 1 is correctly attached to timing pulley U 2 refer to 1 on page 34 and then set the timing belt 1 onto timing pulley D 16 While pushing the timing belt 1 in the direction of the arrow turn the pulley 14 t...

Page 43: ...houlder screw 6 as shown in the illustration 4 Install knee lifter connecting rod D 1 to the knee lifter lever 7 with the shoulder screw 8 5 Install the spring 9 to the shoulder screw 6 so that it faces as shown in the illustration 6 Hook the bent end of the spring 9 onto the knee lifter lever 7 6 7 Needle bar and thread take up mechanism 1 Insert the thread take up support shaft 1 into the machin...

Page 44: ... the pulley back and forth two or three times by about 90 The upper shaft will turn and the thread take up assembly 3 will move into position After doing this provisionally tighten the set screw 7 on the face plate 6 Gently move the thread take up lever 8 to the left and right and check that there is a small amount of sideways play in the thread take up lever 8 7 Set the thread take up support sha...

Page 45: ... bar bush U 10 12 Insert the slide block 12 into the groove in the arm so that the bevelled side is facing inward 13 Insert the needle bar clamp 13 into the crank rod 14 and the slide block 12 14 Insert the needle bar 9 into the arm from above 15 Set the needle bar 9 so that the screw hole D is facing toward the pulley 16 Turn the pulley to set the needle bar 9 to its lowest position and then alig...

Page 46: ...he arm 7 Place the washer 8 onto the shaft 1 and then install retaining ring E 5 to the right side groove 8 Insert the presser bar 10 through the top of the arm and insert it into the bush 11 9 Attach the wick 12 to the presser bar 10 10 Install the guide bracket 13 to the arm and to the presser bar 10 11 Install the thread guide 14 to the guide bracket 13 and provisionally tighten it with the bol...

Page 47: ... the pulley turning direction and then secure the collar 3 by tightening the two set screws 5 Check that the feed rocker shaft 1 moves smoothly with no play 4 Remove the wedge and then tighten the screw 6 of the feed rocker arm 4 Check that the feed regulator 7 moves easily 5 Insert the rubber cap 8 into the hole in the right side of the gear box 6 10 Spring 1 Insert the eccentric pin 1 into the c...

Page 48: ...n the feed lifting eccentric wheel assembly 8 and then insert the feed lifting rock bracket stud 10 8 Align the O mark of the feed lifting rock bracket stud 10 with the reference line on the feed lifting eccentric wheel assembly 8 and then tighten the set screw 11 Figure A 9 Align the O mark of the feed lifting eccentric wheel 12 with the reference line on the lower shaft 9 and then tighten the tw...

Page 49: ...e illustration Be careful not to bend the oil gauge 3 at this time 2 Insert all of the oil tubes 4 containing the wicks through the hole in the arm bed 3 Route the oil tube 4 as shown in the illustration 4 Use piano wire or similar to pass the wick in the oil tube 4 through the thread take up support shaft 5 5 Use your finger to check that the end of the oil tube 4 is inserted into the hole in the...

Page 50: ...to the arm so that it faces as shown in the illustration and then tighten the set screw 2 2 Insert the tension release stud 3 into the mounting hole 3 Insert the pin 5 into the thread tension bracket assembly 4 then insert it into the mounting hole and tighten the set screw 6 4 Install the arm thread guide 7 with the screw 8 Tighten the screw 8 so that it comes to about the center of the arm threa...

Page 51: ...cam lever shaft 4 into the bed so that the groove is at the right 3 Install the rubber cushion 5 collar 6 and spring 7 to the thread trimmer cam lever shaft 4 4 With the slide block of the thread trimmer cam lever 8 set into the forked shaft 1 insert the thread trimmer cam lever shaft 4 into the thread trimmer cam lever 8 5 Push the thread trimmer cam lever 8 to the left and then place the washer ...

Page 52: ...s 24 For DD7100A 710A At this time install the stopper bracket 25 with two of the screws 24 also Push the solenoid lever 22 to the left and check that the solenoid lever 22 can move sideways by 5 6 mm 6 15 2 Adjusting the needle and feed mechanism timing Adjust so that the needle 3 is positioned as described below depending on the sub class when the feed dog 1 drops from its highest position until...

Page 53: ...adjust the position of the needle 3 in accordance with the sub class when the needle is moving down from its highest position 6 Tighten the two set screws 5 four set screws for the DD7100 6 15 3 Installing the movable knife and fixed knife 1 Remove the needle plate and the needle 2 Install the movable knife 1 to the movable knife holder 3 with the two pan screws 2 3 Tilt back the machine head 4 In...

Page 54: ...o the right Figure B Tighten the set screw 5 at a torque of approximately 4 N m Movable knife and fixed knife position adjustment 1 Turn the pulley and push the thread trimmer solenoid 1 with a finger 2 While doing this turn the pulley again until the roller shaft 4 of the thread trimmer cam lever assembly 3 is sitting on top of the thread trimmer cam 2 In this position move the thread trimmer lev...

Page 55: ...being used to pass comfortably in between 5 Adjust the needle and high speed rotary hook 2 timing 1 Install the needle 2 Turn the pulley raise the needle bar 1 8 mm or 2 2 mm for sub class 5 from its lowest position reference line a position so that reference line b is aligned with the bottom of the needle bar bush 7 3 Loosen the three set screws 3 and then adjust the position of the high speed ro...

Page 56: ...between the left and right sides of the feed dog 3 and the needle plate 6 are the same 6 Tilt back the machine head and install the slide plate 8 6 18 Reverse actuator assembly and presser hoot 1 Install the reverse actuator 1 to the arm with the two screws 2 2 Install the presser foot 3 and finger guard 4 to the presser bar with the screw 5 3 Pass the cord 6 of the reverse actuator 1 under the ar...

Page 57: ...on for the tension spring 7 is 6 8 mm 4 6 mm for sub class 5 above the top of the thread guide 5 when the presser foot is lowered 1 Lower the presser foot 2 Loosen the set screw 8 3 Turn the thread tension bracket 9 to adjust the position of the tension spring 7 4 Tighten the set screw 8 Check the forward back position of the thread tension bracket 9 when tightening the set screw 8 6 18 4 Adjustin...

Page 58: ... 1 through the top of the arm and attach it to the tension release plate 3 2 Pass the other end of the tension release wire 1 through the arm as shown in the illustration 3 Secure the tension release wire 1 with the wire holder 4 as shown in the illustration 1786M 1785M 1 2 3 1 1787M 1 4 1 Approx 10 mm 4 ...

Page 59: ...ver screw 6 can be verified when the machine head is restored to its normal position 4 Return the machine head to its normal position and loosen the screw 6 5 Check that the plunger pin 3 is in the groove A in the solenoid lever 6 With the reverse stitching lever 7 lowered all the way push the plunger 5 until the clearance between the setting plate 8 of the quick reverse solenoid 1 and the plunger...

Page 60: ...uced by about 50 ml Use only the lubricating oil Nisseki Mitsubishi Sewing Lube 10N VG10 specified by Brother Do not add more than the specified volume of lubricating oil If you add too much lubricating oil it may result in oil leaks 5 For sub classes 3 and 4 connect the knee lifter connecting rod 6 and the knee lifter arm 7 by tightening the shoulder screw 8 Checking the amount of oil Check the a...

Page 61: ... shaft into the hole 11 at the rear of the oil tank 1 DD7100 1 Install the oil tank 1 to the bed with the two screws 2 2 Place the tube clip 4 onto the oil tube 3 3 Insert the oil tube 3 into the oil gauge guide 5 and clamp it with the tube clip 4 4 Insert oil tube S 6 into the oil feeding pipe 7 and insert oil tube M 8 into the oil feeding pipe 9 5 Insert the oil tube 10 from the horizontal feed ...

Page 62: ... tighten the set screw 8 to secure it in that position At this time the holder 2 should be under the set screw 8 6 24 Ground wire 1 Secure the ground wire 1 to the bed with the screw 2 The ground symbol 3 indicates the location 2 Group the ground wire 1 oil tube 4 DD7100 only and thread trimmer solenoid cord 5 together in that order and secure them together with the cord holder 6 6 25 Operation pa...

Page 63: ... plate 1 to the arm with the three screws 2 2 Install the thread take up cover 3 to the arm with the screw 4 3 Install the needle 5 4 Pass the thread wiper cord 6 under the arm as shown in the illustration 5 Secure the thread wiper cord 6 together with the reverse actuator cord 7 using the cord holder 8 DD7100A 710A DD7100 1800M 2 2 3 1 4 5 8 7 6 6 8 7 1801M 1799M 2 ...

Page 64: ...ssembly 1 Install the arm cover 1 to the arm with the four screws 2 2 Install the rear cover 3 to the arm with the seven screws 4 3 Insert the bobbin wider tension 5 into the mounting hole so that it faces as shown in the illustration and then secure it with the set screw 6 6 29 Other devices Refer to the Instruction Manual for details on installing other devices 1803M 6 3 2 4 5 1 1802M 3 1 2 ...

Page 65: ...ead wiper 5 Quick reverse solenoid 12 Quick reverse solenoid 6 Reverse actuator 13 Reverse actuator 7 Safety switch 14 Safety switch 2 Insert the sewing machine 14P connector 1 the lower thread detector mechanism 8P connector 3 the solenoid type presser lifter connector 4 the synchronizer connector 5 and the operation panel connector 6 into the control box circuit board 3 Insert the motor connecto...

Page 66: ...g oil does not overflow from the oil filler hole 1 2 Check that the oil gauge comes to the upper reference line in the oil gauge window 3 DD7100 1 Remove the oil tank cap 1 and pour in 120 ml of lubricating oil from the accessory oil bottle 2 Use the reference line as a guide when pouring 2 Replace the oil tank cap 1 3 Return the machine head to its original position 4 Check that the oil gauge com...

Page 67: ...Y SL 710A 60 6 32 Bed cover and knee lifter lever 1 Install the bed cover 1 to the bed 2 For sub classes 30 31 40 and 41 push the knee lifter lever 2 onto the knee lifter shaft 3 1809M 3 1 2 DD7100A 710A DD7100 ...

Page 68: ...o position C 2 After pressing the treadle forward check that the needle is lowered to the top of the needle plate when the treadle is returned to the neutral position A when needle down stopping has been set 3 If the treadle is pressed to position D or if it is pressed to position D and then returned to the neutral position A thread trimming is carried out and the needle then rises above the needl...

Page 69: ... safety switch 1 and the table hole is 4 5 mm If the clearance is too great place a washer 2 on the machine head side as shown in figure B and re install the safety switch 1 If the position cannot be satisfactorily adjusted in this way add more washers of the same thickness 1810M 1 2 B A 1 2 Table Machine bed 4 5 mm 1 25 mm 1811M By changing the position of the safety switch the required spring st...

Page 70: ...serve all safety precautions 7 1 Adjusting the thread tension spring Thread tension spring position The standard position of the thread tension spring 1 is 6 8 mm 4 6 mm for 5 models above the surface of the thread guide 3 when the presser foot 2 is lowered 1 Lower the presser foot 2 2 Loosen the set screw 4 3 Turn the thread tension bracket 5 to adjust the spring position 4 Securely tighten the s...

Page 71: ...justing the presser foot height The standard height of the presser foot 1 is 6 mm when the presser foot 1 is raised by means of the presser bar lifter 2 1 Loosen the nut 3 of the adjustment screw 4 and then turn the adjustment screw 4 so that there is no pressure applied to the presser foot 2 Raise the presser bar lifter lever 2 The presser foot 1 will also rise 3 Remove the oil cap 5 4 Loosen the...

Page 72: ...tud 3 within a range of 90 from the reference line 4 to adjust the vertical height of the feed bar 5 Fig A 5 Tighten the screw 2 If you are worried about the angle of the feed dog 1 turn the shaft 6 while carrying out the above adjustment Figure B Refer to 7 5 Adjusting the feed dog angle on the next page for details of this operation 1930M 1 1 3 0 8 mm 5 1 2 mm 1815M 1816M Needle plate B A 3 1 2 ...

Page 73: ...er to prevent puckering lower the front of the feed dog 1 In order to prevent the material from slipping raise the front of the feed dog 1 5 Securely tighten the set screws 4 If you would like to tilt the feed dog 1 further turn the feed lifting rock bracket stud 5 while carrying out the above adjustment Figure D Refer to 7 4 Adjusting the feed dog height on the previous page for details of this o...

Page 74: ...should be aligned and the point of the needle should be approximately 1 mm below the needle plate 2 For thick materials The top of the feed dog 1 and the top of the needle plate 2 should be aligned and there should be a clearance of approximately 3 mm between the point of the needle and the needle plate 2 1 Tilt back the machine head Refer to page 8 2 Loosen the two set screws 5 and then turn the ...

Page 75: ...nd the distance from the needle hole to the tip of the rotary hook should be 0 0 5 mm 2 Loosen the set screws 5 and then align the tip of the rotary hook 3 with the center of the needle 4 The distance between the tip of the rotary hook 3 and the needle 4 should be approximately 0 0 05 mm 3 Securely tighten the set screws 5 Checking the clearance between the rotary hook and bobbin case holder posit...

Page 76: ...quick reverse solenoid 4 will become more apparent 7 10 Matching stitch lengths for normal feed and reverse feed The following operation matches the stitch lengths for normal feed and reverse feed 1 Turn the stitch length dial to the 3 setting 2 At a low sewing speed 220 rpm sew using normal feed and using reverse feed 11 stitches in each direction 3 If adjustment is required carry out the followi...

Page 77: ...he top of the needle plate to the tip of the needle is within the value shown in the illustration in accordance with the machine model Adjusting the needle up stop position 1 Turn off the power switch 2 Loosen the screw 1 3 Move the screw 1 in the direction of rotation of the machine pulley to raise the needle bar 2 to a higher stop position Move the screw in the other direction to lower the needl...

Page 78: ...d plunger 1 is released the tension discs 2 close 1 Loosen the nuts 3 and 4 and then push the solenoid plunger 1 by 2 3 mm 2 Tighten the left side nut 3 until the tension discs 2 start to open 3 Check that the tension discs 2 open fully when the solenoid plunger 1 is pushed all the way and that the tension discs 2 close when the solenoid plunger 1 is released 4 Tighten the right side nut 4 B If th...

Page 79: ...g the treadle return pressure 1 Loosen the nut 3 and turn the bolt 4 The treadle return pressure becomes heavier as the bolt 4 is tightened and it becomes lighter as the bolt 4 is loosened 2 Tighten the nut 3 Adjusting the treadle stroke Remove the nut 5 and then move the connecting rod joint 6 from the position in figure A to the position in figure B The treadle stroke will then be increased by a...

Page 80: ...eath the rotary hook 2 and hold it there Then run the sewing machine at the normal sewing speed for 8 seconds Any type of paper can be used as the lubrication amount check sheet 1 3 Check the amount of oil which has spattered onto the sheet Adjusting the lubrication amount 1 Tilt back the machine head 2 Turn the lubrication adjustment screw 3 approximately 45 to adjust the lubrication amount If th...

Page 81: ...ustment screw 3 as far as it will go and then turn it back the other way about three full turns At this time the head A of the lubrication adjustment screw 3 should be almost flush with the edge B of the bed Note If the sewing machine is used while the lubrication adjustment screw 3 is in the fully tightened position it will cause oil to leak out through the gap between the rotary hook shaft 4 and...

Page 82: ...ontrol box 4 and the electrical brake is then applied to slow the DD motor 5 2 The encoder circuit board that is installed to the DD motor 5 sends a signal to the control box 4 so that the electrical brake is applied in order to stop the sewing machine at the stopping position needle up or needle down set by the pulley 6 that is attached to the DD motor 5 C When the treadle is depressed backward 1...

Page 83: ...e present can result in severe injury Removal 1 Remove the cable tie 1 and then disconnect the connectors 2 to 6 from the sewing machine 2 Disconnect the power supply connector 7 and the motor connector 8 3 Loosen the nuts 9 and 10 without removing them 4 Remove the bolt 11 and nut 12 5 Pivot the control box around the bolt 13 and pull it out to remove it from the table Installation Install by fol...

Page 84: ...phase MD 732 DD7100A Three phase MD 7320 SL 710A Three phase Phase Voltage number in brackets indicates factory default setting Serial No NO K01 A11101 Design revision symbol A B C Year of manufacture last two digits of year Month of manufacture A M Type DD7100A DD7100 SL 710A Compliance E 4 or 5 CE compliant N Others None Speed limit speed setting 3 7 3 000 rpm 4 8 3 500 rpm 5 9 4 000 rpm 6 A 4 5...

Page 85: ...111 Design revision symbol A B C Year of manufacture last two digits of year Month of manufacture A M DD7100 SL 710A DD7100A brother MD720A NO G01A11111 brother MD710A NO G97D11111 brother M 72A NO D02A22222 For DD7100A and SL 710A J80829 001 For DD7100 J80625 001 1831M 1832M ...

Page 86: ...ning off the power switch and disconnecting the power cord from the wall outlet before opening the face plate of the control box Touching areas where high voltages are present can result in severe injury Name and function of each part 1 2 3 5 4 6 7 8 9 10 14 12 11 13 15 16 17 18 19 20 21 24 23 22 1833M ...

Page 87: ...ination lamp 6 V DIP switch 18 DSW 8 element DIP switch 1 2 PVR Coordinates the treadle unit 24 and control circuit board 16 2 Control dials 21 FVR Use to adjust the fluorescent tube and lamp if they are flickering when the sewing machine starts 3 6 Red LED Indicates power supply circuit board problems LED indicators 7 Green LED Indicates that the power is on 1 When using the automatic presser lif...

Page 88: ...FF 5 Spare 6 Limited speed setting 1 7 Limited speed setting 2 Maximum sewing speed during high speed sewing that can be through the operation panel See NOTE 3 8 Always set to off See NOTE 4 NOTE 1 Once the knee lifter switch is used to lower the presser foot the foot pedal can not be used to raise the presser foot while the machine is stopped at this time only the knee lifter is able to raise and...

Page 89: ...ed to backtacking Press the thread trimming keys The plus or minus symbol currently selected will blink Select the plus or minus symbol using the key below the B display 4 Press the thread trimming key Parameter number will reappear Changing Completely Indicate parameter number 99 using the and keys below the B display Indicate parameter number 90 Press the thread trimming key End The data current...

Page 90: ... wiper ON time 22 50 50ms 40 70 X1 40 70ms Lower thread detect pin ON control time all areas 23 10 10ms 05 25 X1 5 25ms First ON time for lower thread detect pin 24 07 7ms 01 15 X1 1 15ms First OFF time for lower thread detect pin 26 03 30ms 00 05 X10 0 50ms Time delay from the time the thread wiper turns OFF to the time when the lower thread detect pin turns ON 27 c 05 0 5s 02 50 X0 1 0 2 5 0s Ti...

Page 91: ...epression stroke P5 00 0 mm 06 06 X0 75 4 5 4 5 mm Maximum speed reaching point of depression stroke S4 01 0 25 mm 02 02 X0 50 1 0 1 0 mm Speed change starting point of standing operation variable speed pedal S5 00 0 mm 02 02 X0 50 1 0 1 0 mm Maximum speed reaching point of standing operation pedal With the value being 0 at the treadle neutral position the value is positive when the treadle is dep...

Page 92: ...n the diagram where is a two digit number corresponds to the various parameter numbers Motor Presser foot lifiting Lower thread detector Thread trimming Needle up signal Needle down signal Depressed backward Depressed forward with no lower thread 1838M Thread wiping ...

Page 93: ...r of the two LEDs of the needle up down stop key will be lit to indicate the direction of movement On the B 40 or B 100 operation panel the setting will be indicated on the D display Select the desired memory switch number using the and keys below the AB displays Press the needle up down stop key to change the setting of the memory switch Either of the two LEDs of the needle up down stop key will ...

Page 94: ...up to 5 000 rpm Memory switches 11 18 ON Without thread trimming and thread wiper 11 Thread trimming and thread wiper output OFF With thread trimming and thread wiper ON Presser foot is raised when the foot pedal is in neutral 12 Presser foot position after thread trimming See NOTE 2 OFF Presser foot is lowered when the foot pedal is in neutral ON Presser foot is at its highest position 13 Presser...

Page 95: ...continuous backtacking plus 10 stitches OFF No extra stitches are added Memory switches 31 38 ON Sewing can be suspended by returning the foot pedal to neutral During start backtacking sewing speed depends on the foot pedal stroke 31 Start backtacking suspension by foot pedal being placed in neutral or backtacking speed change during the start backtacking OFF Sewing can not be suspended by returni...

Page 96: ...ifter pedal is used 48 Lifting the presser foot using thread trimming pedal during standing operation OFF It is activated Memory switches 51 58 ON Lower thread is detected while the machine is stopped by putting foot pedal in neutral for the specified time 51 Lower thread detection after the machine is stopped by putting foot pedal in neutral See NOTE 9 OFF Lower thread is not detected after the m...

Page 97: ...r1 are set at the neutral position Carry out the setting in Setting method for standard depression strokes on page 92 F1 and r1 are set at the first modulation point for the depression force Depression force Whendepressed forward and depressed backward The depression force hardly changes at all from the start of depression until full depression Whendepressed forward and depressed backward The depr...

Page 98: ...ng point 6 7 P5 S4 Maximum speed reaching point S5 1 S5 1 S5 Maximum forward depression point 14 5 12 14 5 32 P1 S6 Back automatic presser lifter operating point 2 2 14 P0 S7 Thread trimmer operating point 5 22 5 35 S8 Maximum back depression point 8 28 8 43 1 Enabled when DIP switch 1 is ON and memory switch 13 is ON 2 Enabled when memory switch 13 is OFF When the connecting rod installation posi...

Page 99: ...cuit board are replaced it will be necessary to make new settings according to the procedure described below Use the following procedure to set the operating positions for the depression stroke 1 Signal setting entry 1 Set DIP switch No 8 to ON 2 Turn on the power switch 3 Press the thread trimming key 2 and the AUTO key 3 simultaneously FF will appear in columns A and B 4 of the display window 4 ...

Page 100: ...the display window 2 Press the thread trimming key 2 nn will flash in columns A and B 4 of the display window 3 Memorizing the neutral position Carry out the following procedure while removing your foot from the treadle 1 Check the nn is flashing in columns A and B 4 of the display window 2 Press the thread trimming key 2 rr will flash in columns A and B 4 of the display window 0844M 4 1845M 4 2 1...

Page 101: ...Press the treadle forward until the depression force suddenly becomes heavier and hold the pedal in that position while carrying out the following procedure For treadle unit H If the depression force of the pedal does not change suddenly when it is pressed forward carry out the following procedure with your foot removed from the pedal For treadle unit G 1 Check that F1 is flashing in columns A and...

Page 102: ... out the following procedure with your foot removed from the pedal For treadle unit G 1 Check that r1 is flashing in columns A and B 4 of the display window 2 Press the thread trimming key 2 99 will flash in columns A and B 4 of the display window 7 Completion of setting 1 Check that 99 is flashing in columns A and B 4 of the display window 2 Press the thread trimming key 2 Columns A and B 4 of th...

Page 103: ...before opening the face plate of the control box Touching areas where high voltages are present can result in severe injury 1 Remove the three screws 1 and then remove the treadle unit 2 2 Install the foot plug 3 3 Install the ground wire with the screw 4 4 Insert the connector 5 of the foot plug 3 into the CN3 connector of the control circuit board 5 With the connector 5 passed through the openin...

Page 104: ...Thread trimmer switch 4 SOV 5 Spare 6 Low speed switch 7 Presser foot switch 8 Variable speed input 9 Ground 1866M Note Connector types Manufacturer Connector No Connectorterminal MOLEX 1292 P 1380 TL 1868M 1867M Presser foot Low speed Thread trimming High speed A Two step pedal B Variable speed pedal Presser foot Low speed Thread trimming High speed ...

Page 105: ... After the sewing machine stops it is raised together with the automatic presser lifter and then after 10 seconds it is lowered Note The 40th stitch and 10 seconds settings given above can be changed by changing the parameter settings 15 2 Connector The following puller connector is provided Part name Part code Puller connector assembly J03126 001 Note If purchasing the connector as a single part ...

Page 106: ...he motor will not operate while a L signal is being output from pin 2 of CN6 16 2 Connector The following bobbin changer connector is provided Part name Part code Bobbin changer connector assembly J03136 001 Note If purchasing the connector as a single part from the manufacturer specify the following number Manufacturer MOLEX Connector No 51103 400 Connector terminal 50351 8100 16 3 Binding the co...

Page 107: ... speed 100 Po Stop improvement speed Do not change 1500 100 1 The actual speed for LI is dependent on Sb 2 Sb Start backtacking speed and H High speed can also be set and changed using the operation panel 17 2 Setting method DANGER Wait at least 10 minutes after turning off the power switch and disconnecting the power cord from the wall outlet before opening the face plate of the control box Touch...

Page 108: ... complete turn off the power switch 1 12 Set DIP switch 8 to OFF 17 3 Checking the speed settings While the setting speed is being displayed as described in step 10 above carry out the following operations 1 Press the half stitch key 1 The sewing machine will operate at the set speed 2 Press the half stitch key 1 once more to stop the sewing machine 3 Return to step 10 above Note When checking the...

Page 109: ...ddition the buzzer will sound continuously After this carry out the Confirming the clear below Automatic clearing If the sewing machine s computer judges that the memory data is corrupted when the power is turned on the memory data will be cleared automatically In this case the power indicator on the operation panel will illuminate and CL will appear in the LED display After this both will start f...

Page 110: ... ohmmeter in the x1 range If the value is as shown in the table below the connector is normal Between 2 3 Between 3 4 Between 4 2 Approx 2 3 Ω Power switch 1 Disconnect the power supply connector 6P from the control box 2 Turn on the power switch 3 Measure the voltage at the power supply connector using the AC voltage range of a multimeter and check that the voltage is within the allowable range f...

Page 111: ...nnector 1 Disconnect the solenoid type presser lifter connector 4P from the control box 2 Measure the resistance of the solenoid type presser lifter connector using an ohmmeter in the x1 range If the values are as shown in the table below the connector is normal Between 2 4 Presser lifter solenoid Approx 9 Ω When knee switch is pressed Approx 0 Ω Between 1 3 When knee switch is released Ω Lower th...

Page 112: ...21 WIRING DIAGRAMS SL 710A 105 21 WIRING DIAGRAMS 21 1 Control circuit board assembly 1 6 1889M ...

Page 113: ...21 WIRING DIAGRAMS SL 710A 106 Control circuit board assembly 2 6 1934M ...

Page 114: ...21 WIRING DIAGRAMS SL 710A 107 Control circuit board assembly 3 6 1890M ...

Page 115: ...21 WIRING DIAGRAMS SL 710A 108 Control circuit board assembly 4 6 1891M ...

Page 116: ...21 WIRING DIAGRAMS SL 710A 109 Control circuit board assembly 5 6 1892M ...

Page 117: ...21 WIRING DIAGRAMS SL 710A 110 Control circuit board assembly 6 6 1893M ...

Page 118: ...21 WIRING DIAGRAMS SL 710A 111 21 2 Power supply circuit board assembly DD7100A 710A Power supply circuit board assembly DD7100A 710A D ADD1 110V 1 3 1894M ...

Page 119: ...21 WIRING DIAGRAMS SL 710A 112 Power supply circuit board assembly DD7100A 710A D ADD1 110V 2 3 1895M ...

Page 120: ...21 WIRING DIAGRAMS SL 710A 113 Power supply circuit board assembly DD7100A 710A D ADD1 110V 3 3 1896M ...

Page 121: ...21 WIRING DIAGRAMS SL 710A 114 Power supply circuit board assembly DD7100A 710A D ADD1 240V 1 3 1897M ...

Page 122: ...21 WIRING DIAGRAMS SL 710A 115 Power supply circuit board assembly DD7100A 710A D ADD1 240V 2 3 1898M ...

Page 123: ...21 WIRING DIAGRAMS SL 710A 116 Power supply circuit board assembly DD7100A 710A D ADD1 240V 3 3 1899M ...

Page 124: ...21 WIRING DIAGRAMS SL 710A 117 Power supply circuit board assembly DD7100A 710A D ADD3 220V 1 3 1900M ...

Page 125: ...21 WIRING DIAGRAMS SL 710A 118 Power supply circuit board assembly DD7100A 710A D ADD3 220V 2 3 1901M ...

Page 126: ...21 WIRING DIAGRAMS SL 710A 119 Power supply circuit board assembly DD7100A 710A D ADD3 220V 3 3 1902M ...

Page 127: ...21 WIRING DIAGRAMS SL 710A 120 21 3 Power supply circuit board assembly DD7100 Power supply circuit board assembly DD7100 D NDD1 120V 1 3 1903M ...

Page 128: ...21 WIRING DIAGRAMS SL 710A 121 Power supply circuit board assembly DD7100 D NDD1 120V 2 3 1904M ...

Page 129: ...21 WIRING DIAGRAMS SL 710A 122 Power supply circuit board assembly DD7100 D NDD1 120V 3 3 1905M ...

Page 130: ...21 WIRING DIAGRAMS SL 710A 123 Power supply circuit board assembly DD7100 D NDD1 230V 1 3 1906M ...

Page 131: ...21 WIRING DIAGRAMS SL 710A 124 Power supply circuit board assembly DD7100 D NDD1 230V 2 3 1907M ...

Page 132: ...21 WIRING DIAGRAMS SL 710A 125 Power supply circuit board assembly DD7100 D NDD1 230V 3 3 1908M ...

Page 133: ...21 WIRING DIAGRAMS SL 710A 126 Power supply circuit board assembly DD7100 D NDD3 240V 1 3 1909M ...

Page 134: ...21 WIRING DIAGRAMS SL 710A 127 Power supply circuit board assembly DD7100 D NDD3 240V 2 3 1910M ...

Page 135: ...21 WIRING DIAGRAMS SL 710A 128 Power supply circuit board assembly DD7100 D NDD3 240V 3 3 1911M ...

Page 136: ...21 WIRING DIAGRAMS SL 710A 129 21 4 Transformer 1912M ...

Page 137: ...21 WIRING DIAGRAMS SL 710A 130 21 5 Operation panel B 40 Operation panel B 40 1 3 1913M ...

Page 138: ...21 WIRING DIAGRAMS SL 710A 131 Operation panel B 40 2 3 1914M ...

Page 139: ...21 WIRING DIAGRAMS SL 710A 132 Operation panel B 40 3 3 1915M ...

Page 140: ...21 WIRING DIAGRAMS SL 710A 133 21 6 Operation panel B 100 Operation panel B 100 1 3 1916M ...

Page 141: ...21 WIRING DIAGRAMS SL 710A 134 Operation panel B 100 2 3 1917M ...

Page 142: ...21 WIRING DIAGRAMS SL 710A 135 Operation panel B 100 3 3 1918M ...

Page 143: ...trong Adjust the lower thread tension or upper thread tension Instruction manual 3 Loops appear in seam Is the thread path not smooth enough Use a file with a fine grain or sandpaper to polish smooth the thread path Is the bobbin not turning smoothly Pull out the lower thread to check that there is no slackness in the thread tension or replace the bobbin or bobbin case Instruction manual 4 Skipped...

Page 144: ... Adjust the presser foot pressure Is the feed dog too low Adjust the feed dog height Is the bobbin scratched If the bobbin is damaged smooth it with an oiled grindstone or replace it Instruction manual 65 7 Large degree ofpuckering excess tension Is the upper thread tension too strong Make the upper thread tension as weak as possible Is the lower thread tension too strong Make the lower thread ten...

Page 145: ...hread or lower thread tension Is the upper thread may be loose because the thread tension spring operating range is too small Adjust the position of the thread tension spring Is the rotary hook feed dog or other part damaged If they are damaged smooth them with an oiled grindstone or replace the damaged parts Is the thread path damaged If the thread path is damaged smooth it with sandpaper or repl...

Page 146: ...t the height of the needle bar Adjust the clearance between the needle and the rotary hook Is the needle timing advanced too far with respect to the feed dog Retard the needle timing Instruction manual 67 68 67 15 The stitch lengths in the normal feed direction and reverse feed direction are not equal Is the eccentric pin adjusted properly Adjust the eccentric pin 69 16 An impact noise is heard fr...

Page 147: ...s the treadle unit or control circuit board been replaced Adjust the depression stroke to the standard setting Is operation possible using the standing operation pedal If operation is not possible turn the power off and then back on again 96 92 19 Machine does not operate at high speed Is the sewing speed setting or backtack speed setting incorrect Set the speed to a higher speed using the operati...

Page 148: ...is too long or too many appliances are being run from a single outlet this may cause voltage drops which will in turn cause the reset function to activate and stop the machine even if the power supply itself is normal 103 25 Lower thread detector does not operate Is the lower thread detector connector inside the control box disconnected Insert the connector securely Is the lower thread detector re...

Page 149: ...ply capacity is not sufficient Adjust the FVR inside the control box The flicker is reduced when the FVR is turned to the left The sewing machine start up also becomes slower when this is done 80 30 The illumination lamp does not turn on Is the lamp blown Replace the lamp 6 V Is the 5 A fuse inside the control box blown Replace the 5 A fuse Is the lamp cord disconnected from the terminal board ins...

Page 150: ... 34 Er Has the setting for standard depression strokes been set correctly Repeat the setting for standard depression strokes Treadle unit malfunction Replace the treadle unit 92 96 L Is the motor connector inside the control box disconnected Insert the connector securely Has the machine locked up Turn off the power and then turn the machine pulley by hand and check that it turns easily Instruction...

Page 151: ...wer supply voltage abnormally high Check that the power supply voltage matches the control box voltage specifications 77 P Is connector CN7 or CN8 inside the control box disconnected Securely connect the connectors Problem with control box Replace the control box 80 76 PE Is the treadle unit connector inside the control box disconnected Insert the connector securely Treadle unit malfunction Replac...

Page 152: ...pin 1 Use an Allen key to move the slider 2 and check that the detector pin 1 moves correctly Problem with lower thread detector Replace the lower thread detector Instruction manual Instruction manual Uo Is the lower thread detector connector inside the control box disconnected Insert the connector securely Is there an open circuit in the lower thread detector connecting cord inside the machine he...

Page 153: ...SERVICE MANUAL 15 1 Naeshiro cho Mizuho ku Nagoya 467 8561 Japan Phone 81 52 824 2177 Printed in Japan 117 S11 I2010820H 2002 09 H 1 ...

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Brother DB2-DD7100, Service Manual

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