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SERVICE MANUAL SL-710A DB2-DD7100A DB2-DD7100 Please read this manual before making any adjustments. SINGLE NEEDLE DIRECT DRIVE STRAIGHT LOCK STITCHER WITH THREAD TRIMMER...
As a result of research and improvements regarding this product, some details of this manual may not be the same as those for the product you purchased. If you have any questions regarding this product, please contact a Brother dealer. SAFETY INSTRUCTIONS...
Contact your Brother dealer or a qualified electrician for any electrical work that may need to be done. Use both hands to hold the machine head when tilting it back or returning it to its original position.
Ask your Brother dealer or a qualified electrician to carry out any maintenance and inspection of the If the power switch needs to be left on when electrical system.
The following warning labels appear on the sewing machine. Please follow the instructions on the labels at all times when using the machine. If the labels have been removed or are difficult to read, please contact your nearest Brother dealer. Thread take-up cover...
2.OPTIONAL PARTS 2. OPTIONAL PARTS Part name Part code DD7100A, 710A S80008-001 Presser foot lifting solenoid set A With knee switch DD7100 183959-001 DD7100A, 710A S80009-001 Presser foot lifting solenoid set B Without knee switch DD7100 183960-001 DD7100A, 710A S80007-001 Lower thread detector set DD7100 183955-001...
3. NOTES ON HANDLING 3. NOTES ON HANDLING About the machine set-up location • Do not set up this sewing machine near other equipment such as televisions, radios or cordless telephones, otherwise such equipment may be affected by electronic interference from the sewing machine.
4. MECHANICAL DESCRIPTIONS 4. MECHANICAL DESCRIPTIONS The mechanisms operate in the order of the numbers given in the illustrations. 4-1. Upper shaft and needle bar mechanism Needle take-up lever Upper shaft Thread take-up crank Rotor Pulley Needle bar clamp Slide block Needle bar The needle bar is guided by the needle bar bush U (1) and needle bar bush D (2).
4. MECHANICAL DESCRIPTIONS 4-3. Feed mechanism 1628M Vertical movement of feed bar Pulley F-lifting eccentric wheel assy Feed bar Lower shaft Horizontal movement of feed bar Pulley Level feed eccentric wheel Level feed Lower shaft connecting rod Feed bar Feed regulator assy Feed rocker bracket arm Feed 1629M...
4. MECHANICAL DESCRIPTIONS 4-4. Quick reverse mechanism 1630M Quick reverse solenoid Solenoid lever ctuator Shaft Handle shaft arm Connecting rod Stud arm F-regulator connecting rod S Feed regulator assy Feed rocker shaft Joint Feed rocker arm Feed rocker arm link <Reverse feed>...
4. MECHANICAL DESCRIPTIONS 4-5. Lubrication mechanism (Thread take-up lever and rotary hook) The lubrication mechanism for this sewing machine is a dry head method, with the oil supplied from a tank. The oil level can be checked through the oil gauge window, without needing to tilt back the machine head or operate the sewing machine.
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4. MECHANICAL DESCRIPTIONS DD7100 When adding the lubricating oil for the first time after unpacking the sewing machine, pour 120 ml of lubricating oil in through oil filler hole (1). The oil gauge in the oil gauge window (2) will rise as far as the upper reference line. (Refer to page 59 for details on the lubrication method.) 1637M Upper reference line...
4. MECHANICAL DESCRIPTIONS 4-6. Thread trimmer mechanism 4-6-1. Thread trimmer operation The figure below shows the thread trimmer without the high-speed rotary hook. 1) When the thread trimmer signal is received Solenoid plunger Solenoid lever Thread trimmer cam lever shaft Roller (Moves over thread trimmer cam (1)) 1639M...
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4. MECHANICAL DESCRIPTIONS 3) Thread trimming complete stop 1641M Solenoid Thread trimmer lever plunger <1> Thread trimmer lever <2> Forked shaft <3> Roller block Solenoid lever <4> Roller Thread trimmer lever Thread trimmer holder Thread trimmer connecting rod Spring Movable knife 4) Thread trimmer safety device When the movable knife does not return to its original position, the mechanism operates as shown in the illustration below to move the movable knife to a position where it will not touch the needle.
4. MECHANICAL DESCRIPTIONS 4-6-2. Upper and lower thread trimming Movable knife 1643M 1644M 1. When the needle rises 1.8mm (2.2mm with heavy- 2.The thread trimmer signal is then relayed, and the weight materials) above the down position the rotary thread trimmer cam drives the movable knife. The hook point catches the loop formed by the needle.
4. MECHANICAL DESCRIPTIONS 4-8. Thread wiper mechanism When a thread wiping signal is received after the thread is trimmed Thread wiper solenoid (Spring) Thread wiper rod Thread wiper crank assy Thread wiper 1654M 4-9. Presser foot lifter mechanism (-9[][], Option) (built into machine head) 1655M When knee switch is pressed Knee lifter connecting rod...
4. MECHANICAL DESCRIPTIONS 4-10.Lower thread detector mechanism • The lower thread detector mechanism has been designed for materials which do not allow thread jointing or re-sewing to be carried out when the lower thread runs out. • The lower thread is detected after the thread is trimmed, and the amount of lower thread remaining is displayed on the operation panel.
5. DISASSEMBLY 5. DISASSEMBLY 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.
5. DISASSEMBLY 1676M <DD7100> Felt Screw [Loosen] Bed under cover Oil gauge guide Oil tubes Oil tank 1675M Screws [2 pcs] -3[][] • -4[][] Lubricating oil Lubricating Screw 1) Place a dish under the lubricating oil outlet, and then remove the screw and drain the lubricating oil.
5. DISASSEMBLY 5-16. Presser foot mechanism 1686M Adjusting screw Spring guide Spring Washer Thread guide Bolt Presser bar [Pull upward] Guide bracket Screw Wick Set screw [Loosen] Shaft [Slide to the right] Spring Washer Retaining ring E Shaft [Pull toward the outside] Tension release plate Retaining ring E 1688M...
5. DISASSEMBLY 5-18. Needle bar and thread take-up mechanism Rubber cap Rubber cap Set screws [2 pcs: Loosen] Set screw [Loosen] Set screws [3 pcs: Loosen] Thread Needle bar bush U take-up assy Crank Needle bar clamp Screw [Loosen] Needle bar Slide block 1691M 5-19.
5. DISASSEMBLY 5-20. Timing belt Flange [DD7100 only] [DD7100 only] Screws [3 pcs: DD7100 only] Timing belt Timing belt [Remove from timing pulley D] 1696M [Remove from the arm] Note; For the DD7100A and 710A, the fan and flange do not need to be removed. 1695M 5-21.
5. DISASSEMBLY 5-24. Stitch length dial 1701M Spring Stitch length dial [Turn counterclockwise all the way] Positioning pin Lock lever [Unlock: DD7100A, 710A only] Positioning pin [Push with a screwdriver or similar] Stitch length dial Stopper [Turn counterclockwise [Turn the stitch length dial counterclockwise again so that and remove] the stopper goes past the positioning pin] 1703M...
Keep the oil out of the reach of children. Use only the proper replacement parts as If the power switch needs to be left on when specified by Brother. carrying out some adjustment, be extremely careful to observe all safety precautions.
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6. ASSEMBLY 4. Turn the stitch length dial (6) clockwise all the way. 5. Push the positioning pin (5) with a screwdriver or similar, and then turn the stitch length dial (6) clockwise again so that the stopper (7) passes to the right of the positioning pin (5).
6. ASSEMBLY 6-2. Rotary hook shaft, thread trimmer cam and gear 1. Insert the rotary hook shaft (1) into the arm so that the screw stops are at the right, and then place the thread trimmer cam (2) onto the rotary hook shaft (1) so that it faces as shown in the illustration.
6. ASSEMBLY 6-4. Lower shaft, lower shaft gear and feed regulator set 1. Hold the lower shaft (1) so that it faces as shown in the illustration, insert it into the arm, and pass it trough the <DD7100> lower shaft gear (2) and the level feed eccentric wheel (3) of the feed regulator assembly inside the gear box.
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6. ASSEMBLY 9. Push back the feed regulator (13) as shown in the 1719M illustration, set so that the lower set screw (14) is facing toward the front, align it with the screw stop of the stud arm (11) and then tighten the set screw (14). (13) * Tighten the set screw (14) so that the stud arm (11) and joint (12) turn smoothly with no play.
6. ASSEMBLY 15. Align the lower set screw (22) and the set screw (7), then align the lower set screw (22) with the screw stop of the lower shaft (1) and tighten the set screw (22). At (23) this time, make sure that the movement of the feed regulator (13) does not become stiffer.
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6. ASSEMBLY 5. Tighten the two motor-side screws (12) of the joint. * At this time, align the screw stop of the rotor (13) Screw stops (13) with the upper set screw (12). (12) 1726M 6. Set the rotor (13) so that the screw stop is facing upward, and then install the pulley (14).
6. ASSEMBLY 6-6. Knee lifter lever mechanism 1. Move the knee lifter connecting rod D (1) as far to the left as possible, and then insert knee lifter lever D (2) into the arm bed. 2. Insert lever shaft D (3) into knee lifter lever D (2) from underneath, and then attach retaining ring E (4).
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6. ASSEMBLY 3. Set the thread take-up crank (5) so that line (A) is at a 1734M right angle to line (B) on the crank (2), and then while pushing the crank (2), tighten the set screw (6). (At this time, align the screw stop of the crank (2) with the set screw (6) when tightening it.) Approx.
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6. ASSEMBLY 8. Insert the needle bar (9) into the arm from above. 9. Tap needle bar bush U (10) into the arm so that the hole (C) is facing toward the pulley. * Tap in needle bar bush U (10) while checking that the needle bar (9) can move up and down (10) smoothly.
6. ASSEMBLY 6-8. Presser foot mechanism 1. Insert the shaft (1) into the arm. 2. Place the tension release plate (2) and the washer (3) onto the shaft (1). 3. Place the presser bar lifter lever (4) onto the shaft (1). 1741M 4.
6. ASSEMBLY 6-9. Feed rocker shaft 1. Place the washer (2) onto the feed rocker shaft (1), 1744M and then insert the feed rocker shaft (1) into the arm. * Insert the feed rocker shaft (1) so that the screw stop (A) of the feed rocker shaft (1) is facing upward and the oil tube hole (B) is facing downward.
6. ASSEMBLY 6-11. Feed bar mechanism 1. Install the feed dog (1) to the feed bracket assembly (2) with the two screws (3). 1748M 2. Place the feed bracket assembly (2) onto the feed (14) 1749M rocker shaft (4). 3. Insert the wick (5) into the hole in the feed rocker shaft (4), and then insert the oil cap (6).
6. ASSEMBLY 6-12.Sub tank, wick holder and wick <DD7100A, 710A> <DD7100A, 710A> 1. Install the sub tank (1) to the arm bed with the two screws with washer (2). * Be careful not to bend the oil gauge (3) at this time. 2.
6. ASSEMBLY 7. Install the wick holder (8) to the arm with the two screws (9). 8. Tie together the wick that is coming out from the wick holder (8) and the wick that is coming out from the thread take-up support shaft (5). 9.
6. ASSEMBLY 6-14. Oil (Feed rocker shaft) 1. Secure the end of the wick in the oil tube (1) using a clip (2) or similar as shown in the illustration. (This is to prevent the wick from being pulled into the oil tube.) 2.
6. ASSEMBLY 8. Place the spring (13) onto the bush (14) so that it faces as shown in the illustration. (14) 9. Place the thread trimmer lever (15) onto the bush (14). (13) (15) * It will be easier to do this if you insert a screwdriver or similar into the gap.
6. ASSEMBLY 1. Install the needle (3) to the needle bar with the screw 1765M 1766M (4). 2. Tilt back the machine head. 3. Loosen the two set screws (5) [four set screws for the DD7100]. Timing pulley D 4. Turn the feed lifting eccentric wheel (6) toward you so that the feed dog (1) moves down from its highest position until it is level with the top of the needle plate (2).
6. ASSEMBLY 6-15-4. Adjusting the thread trimming timing Remove the fed dog. Needle bar lowest position Raised 5 mm Thread trimmer cam position adjustment 1. Turn the pulley to raise the needle bar 5 mm from its lowest position (reference line (a) position) so that reference line (b) is aligned with the bottom of the Reference line (b) Reference line (a)
6. ASSEMBLY 6-16. Rotary hook and bobbin case holder position bracket 1. Remove the feed dog. 2. Tilt back the machine head. 3. Place the high-speed rotary hook (2) onto the rotary hook shaft (1), and provisionally secure it with the three set screws (3).
6. ASSEMBLY 6-17. Ruler plate and needle plate 1. Remove the needle for safety while working. 2. Install the ruler plate (1) to the bed with the screw (2). 3. Install the feed dog (3) to the feed bar (4) with the two screws (5).
6. ASSEMBLY 6-18-1. Adjusting the presser foot height The standard height for the presser foot (1) is 6 mm when the presser foot (1) is raised by the presser bar lifter (2). 1. Raise the presser foot (1) using the presser bar lifter (2).
6. ASSEMBLY 6-19. Tension release wire 1. Insert the terminal (2) end of the tension release wire 1785M (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.
6. ASSEMBLY 6-20. Quick reverse solenoid 1. Pass the cord (2) of the quick reverse solenoid (1) under the bed. 2. Install the quick reverse solenoid (1) to the arm with the three screws (4) so that the plunger pin (3) fits into the groove (A) in the solenoid lever.
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.
6. ASSEMBLY 6-22. Oil tank <DD7100A, 710A> 1. Install the oil tank (1) to the bed with the two screws (2). (11) 2. Place the tube clip (4) onto the oil tube (3). (10) 3. Insert the oil tube (3) into the sub tank (5), and clamp it with the tube clip (4).
6. ASSEMBLY 6-23. Tension release wire 1. With the holder (2) installed to the tension release wire 1795M (1), pass the tension release wire (1) around the wire holder (3) and install it to the solenoid lever (5) with the two nuts (4).
6. ASSEMBLY 4. Pass the cord (2) of the operation panel (1) under the arm as shown in the illustration. 1799M 6-26. Face plate and thread take-up cover 1. Install the face plate (1) to the arm with the three screws (2).
6. ASSEMBLY 6-27. Safety switch 1. Tilt back the machine head. 2. Install the safety switch (1) to the bed with the washer (2) and screw (3). 1802M 6-28. Arm cover, rear cover and bobbin winder tension assembly 1. Install the arm cover (1) to the arm with the four screws (2).
6. ASSEMBLY 6-30. Connectors 1. Insert the pins for the solenoid cords and the safety 1804M switch cord into the sewing machine 14P connector (1). • Match the numbers on the sewing machine 14P connector (1) with the numbers (tube marks) (2) on each pin.
6. ASSEMBLY 6-31. Lubrication Use only the lubricating oil (Nisseki Mitsubishi Sewing Lube 10N; VG10) specified by Brother. <DD7100A, 710A> 1. Pour 130 ml of lubricating oil from the accessory oil bottle (2) in through the oil filler hole (1).
6. ASSEMBLY 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). (DD7100A,710A) (DD7100) 1809M SL-710A...
6. ASSEMBLY 6-33. Test operation CAUTION Do not touch any of the moving parts or press any objects against the machine while sewing, as this may result in personal injury or damage to the machine. For machines with a lower thread detector, set the lower thread remainder limit before carrying out test operation.
6. ASSEMBLY 6-34. Adjusting the safety switch position The safety switch (1) is normally installed as shown in 1810M figure (A). However, if the processing method used for the table leaves too much space between the machine head and the table hole, it may adversely affect the operation of the safety switch (1).
Ask your Brother dealer or a qualified electrician to result in injury. carry out any maintenance and inspection of the When carrying out inspection, adjustment and electrical system.
7. ADJUSTMENTS 7-2. Adjusting arm thread guide R The standard position of arm thread guide R (1) is the position where the screw (2) is in the center of the adjustable range for arm thread guide R. (1). Becomes greater Becomes less * To adjust the position, loosen the screw (2) and then move arm thread guide R (1).
7. ADJUSTMENTS 7-4. Adjusting of the feed dog height The standard height of the feed dog (1) when it is at its <-[][]1, -[][]3> maximum height above the top of the needle plate is 0.8 0.8 mm mm for -[][]1/[][]3 models, and 1.2 mm for -[][]5 models. <-[][]5>...
7. ADJUSTMENTS 7-5. Adjusting the feed dog angle The standard angle for the feed dog (1) when it is at its highest position above the needle plate is when the “ ” mark (or V groove) on the shaft (2) is aligned with the feed rocker bracket arm (3) and the feed dog (1) is parallel to the needle plate.
7. ADJUSTMENTS 7-6. Adjusting the needle bar height Reference line (a), which is the second line from the 0924M bottom of the needle bar (1)(fourth line from the bottom when using a DA X 1 needle) should be aligned with the lower edge of the needle bar bush D (2) as shown in the illustration when the needle bar (1) is at its lowest position.
7. ADJUSTMENTS 7-8. Adjusting the needle and rotary hook timing The tip of the rotary hook (3) should be aligned with the 0928M 0929M center of the needle (4) when the needle bar (1) moves up from its lowest position to the position where reference 0 - 0.5 mm line (b), which is the line at the bottom of the needle bar (1) (third line from the bottom when using a DA X 1...
7. ADJUSTMENTS 7-9. Quick reverse mechanism 1. Turn the stitch length dial to the maximum setting. 2. Remove the rear cover. 3. Tilt back the machine head. 4. Check that the position of the solenoid lever screw (1) can be verified when the machine head is restored to its normal position.
7. ADJUSTMENTS 7-11. Synchronizer Adjustment The synchronizer uses a single element to detect the 0931M needle up stop position. The needle down single is fixed. Checking method Needle down position 1. Turn on the power switch. 2. Stop the machine with the needle in the needle down position.
7. ADJUSTMENTS 7-12. Adjusting the tension release wire If the tension discs stay open or if the upper thread pulls 1824M Open out of the needle after thread trimming, carry out the following adjustments. 2 - 3 mm * Lower the presser foot when making these Opening...
7. ADJUSTMENTS 7-13. Adjusting the treadle Adjusting the treadle pressure 0939M If the machine starts running at low speed when your foot is simply resting on the treadle, or if the treadle pressure is felt to be too weak, adjust the position (a to c) at which the treadle spring (1) is hooked onto the treadle lever (2).
7. ADJUSTMENTS 7-14. Adjusting the rotary hook lubrication amount CAUTION Be careful not to touch your fingers or the lubrication amount check sheet against moving parts such as the rotary hook or the feed mechanism when checking the amount of oil supplied to the rotary hook, otherwise injury may result.
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7. ADJUSTMENTS When changing from the normal rotary hook to the rotary hook RP (lubrication-free rotary hook) 1. While referring to the instruction manual, replace the 0937M rotary hook RP and the cap screw. 2. Tighten the lubrication adjustment screw (3) as far as it will go, and then turn it back the other way about three full turns.
8. CONTROL SYSTEM 8. CONTROL SYSTEM 1825M Turn on the power switch (1). A. When the treadle is depressed 1. When the treadle (2) is depressed, a voltage corresponding to the amount of treadle depression is transmitted by the treadle unit (3) to the control box (4). 2.
9. REMOVING AND INSTALLING THE CONTROL BOX 9. REMOVING AND INSTALLING THE CONTROL BOX 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.
10. CONTROL BOX AND MOTOR RATING PLATE 10. CONTROL BOX AND MOTOR RATING PLATE Control box • Check the phase, voltage and type for the control box. • Some specifications are identical for both single- and three-phase. Model MD-721:DD7100/Single-phase MD-722: DD7100A/Single-phase MD-7220:SL-710A/Single-phase MD-731:DD7100/Three-phase MD-732: DD7100A/Three-phase...
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Serial No. NO. G 0 1 A 11111 Design revision symbol (A, B, C...) Year of manufacture (last two digits of year) Month of manufacture (A - M) DD7100A DD7100 brother brother MD720A MD710A NO. G01A11111 NO. G97D11111 SL-710A brother M-72A NO.
11. CONTROL CIRCUIT BOARD 11. CONTROL CIRCUIT BOARD 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.
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11. CONTROL CIRCUIT BOARD Name Function Connectors Operation panel connector Connect to sewing machine connectors. Synchronizer connector (10) Lower thread detector connector (11) Sewing machine connector (12) Solenoid-type presser lifter connector Coupler connector Connect to power supply circuit board connectors. Relay connector Treadle connector Connect to treadle unit connector.
12. FUNCTION SETTING METHODS 12. FUNCTION SETTING METHODS 12-1. DIP switch functions 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.
12. FUNCTION SETTING METHODS 12-2. Parameter setting flowchart Start • Set memory switch 01 to ON. *1 • Turn off all LEDs. For the B-100 operation panel, select pattern 1. • Leave the machine stopped after thread trimming. • Press the thread trimming and AUTO keys.
12. FUNCTION SETTING METHODS 12-3. Parameters The parameter numbers appear on the panel. Parameter No.10 - 33 Parameter No. Default value Data value setting range Function Time delay from the time the machine starts to operate 15 (150 ms) 00 - 25 [X10] (0 - 250 ms) with the automatic presser foot raised to the time the moter operates.
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12. FUNCTION SETTING METHODS Parameter No.P0 - S5 Parameter Default value Data value setting range Function 00 (0 mm) -07 - 07 [X0.25] Thread trimmer operating point of depression stroke (-1.75 - 1.75 mm) -01 (-0.25 mm) -05 - 05 [X0.25] Back automatic presser lifter operating point of (-1.25 - 1.25 mm) depression stroke...
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12. FUNCTION SETTING METHODS <Parameter time setting> “T** ” in the diagram (where “**” is a two-digit number) corresponds to the various parameter numbers. Depressed forward Depressed backward Needle down signal Needle up signal Thread trimming (with no lower thread) Thread wiping Lower thread detector...
12. FUNCTION SETTING METHODS 12-4. Memory switch setting flowchart Start • Leave the machine stopped after thread trimming • Turn off all LEDs (except for the LED of the needle up/down stop key). (For the B-100 operation panel, select pattern 1.) •...
12. FUNCTION SETTING METHODS 12-5. Memory switches Memory switches 01 - 08 Parameter setting can be changed. Parameter setting Parameter setting change is prohibited. Forward step is possible during backward step (for thread trimming). Interlocking along with forward step Forward step is impossible during backward step (for thread trimming).
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12. FUNCTION SETTING METHODS Memory switches 21 - 28 Start backtacking is performed in the order of lengths A, B, A, then B. Double start backtacking Start backtacking is performed in the order of lengths A and B. End backtacking is performed in the order of lengths C, D, C, and D (B, A, B, and A on the B-20 operation panel).
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12. FUNCTION SETTING METHODS Memory switches 41 - 48 Foot pedal can be used after lower thread alarm. Mode after lower thread alarm After lower thread alarm, the foot pedal operation is deactivated until the cancel key is pressed. Rotary hook used with the lower 1.7-time rotary hook thread detector Standard rotary hook...
13. TREADLE UNIT ASSEMBLY 13. TREADLE UNIT ASSEMBLY 13-1.Types • Two different types are available: a type that controls the automatic presser lifter, and a type does not control the automatic presser lifter. • The two specifications are changed over by (A) changing the attachment position of the spring (1) inside the treadle unit, and (B) resetting the depression stroke signal.
13. TREADLE UNIT ASSEMBLY 13-2.Standard setting values Parameter Symbol Specification Treadle unit G Treadle unit H (diagram Operation Does not control automatic Controls automatic presser lifter below) presser lifter Spring position setting forward/back step Forward/back 1st step modulation modulation (Figure (Figure [b] on previous page) previous page) Function...
13. TREADLE UNIT ASSEMBLY 13-3. Setting method for standard depression strokes CAUTION If the power switch needs to be left on when carrying out some adjustment, be extremely careful to observe all safety precautions. When the specifications of the treadle unit are changed or if the treadle unit or control circuit board are replaced, it will be necessary to make new settings according to the procedure described below.
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13. TREADLE UNIT ASSEMBLY 2) Memorizing the maximum forward position • Carry out the following procedure while pressing the treadle forward as far as it will go. 0844M 1. Turn the PVR so that “45” appears in columns A and B (4) of the display window.
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13. TREADLE UNIT ASSEMBLY 4) Memorizing the maximum backward position • Carry out the following procedure while pressing the treadle backward as far as it will go. 1850M 1. Check that “rr” is flashing in columns A and B (4) of the display window.
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13. TREADLE UNIT ASSEMBLY 6) Memorizing the modulation position when pressing the treadle backward Press gently • Press the treadle backward until the depression force suddenly becomes heavier, and hold the pedal in that position while carrying out the following procedure. (For treadle unit H) •...
14. STANDING OPERATION PEDAL 14. STANDING OPERATION PEDAL Some sub-classes are not equipped with <With foot plug set> <Without foot plug set> a foot plug set. In such cases, install the foot plug set (J02953-001) by the following procedure. Foot plug 1861M 1862M 14-1.
15. Puller (commercially available) 15. Puller (commercially available) 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. AUTO BOBBIN CHANGER 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.
17. SPEED SETTING METHODS 6. Press the sewing speed key (5). 7. The "t" (Thread trimming speed) symbol will appear in LED display AB (4). 1879M 8. In this way, the symbol and the corresponding speed LED display will appear in the order given in the "Types of speed settings"...
18. CLEARING THE MEMORY DATA 18. CLEARING THE MEMORY DATA Types of data that are cleared Clearing the memory data returns all of the following data items to the factory default settings. • Panel settings • Memory switch settings • Parameter settings •...
19. CHECKING THE MOTOR AND POWER SUPPLY 19. CHECKING THE MOTOR AND POWER SUPPLY CAUTION Turn off the power and disconnect the power plug from the wall outlet before carrying out these operations, otherwise the sewing machine may operate if the treadle is pressed by mistake, and injury may result. If the power switch needs to be left on when carrying out some adjustment, be extremely careful to observe all safety precautions.
20. CHECKING THE SOLENOIDS 20. CHECKING THE SOLENOIDS 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.
• Please check the following points before calling for repairs or service. • If the following suggestions do not solve the problem, turn off the machine power supply and contact your nearest Brother service center. 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.
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22. TROUBLESHOOTING Problem Possible cause Page • Are the thread tension spring tensions too strong? 5. Skipped stitches at sewing start Reduce the tension of the thread tension springs. • Is the thread tension spring operating range too large? Thread unravelling at sewing start Lower the position of the thread tension spring.
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• Is the bobbin turning smoothly? thread If the bobbin is not turning smoothly, replace the bobbin. • Is a bobbin other than the light-alloy bobbins specified by Brother being 0751M used? Use only bobbins which are specified by Brother.
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22. TROUBLESHOOTING Problem Possible cause Page • Is the resistance between terminals 3 - 4 of the sewing machine 13. Movable knife does not operate. connector normal? Measure the resistance between terminals 3 - 4 of the sewing machine connector with an ohmmeter. If the measured value is not normal, replace the thread trimmer solenoid.
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22. TROUBLESHOOTING Problem Possible cause Page • Is the power supply connector 18.Machine does operate when power is disconnected from the control turned on and treadle box? is pressed. Insert the connector securely. Instruction manual 1) Operating panel power indicator does 1002M illuminate.
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22. TROUBLESHOOTING Problem Possible cause Page • Is DIP switch 2 inside the control 22. Sewing machine starts operating before box set to OFF? presser foot is lowered Set DIP switch 2 to ON. (solenoid-type presser lifter specifications). 1921M • Is the solenoid-type presser lifter 23.
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22. TROUBLESHOOTING Problem Possible cause Page • Is memory switch No. 11 set to ON? The thread trimmer and thread wiper solenoids Set memory switch No. 11 to OFF. do not operate. • Are the solenoid resistances normal? If the resistances are not normal, replace the solenoids. •...
22. TROUBLESHOOTING 22-2. Error code displays If an error code is flashing on the operation panel display Error code Possible cause Page • Is the bobbin changer power switch turned on? Turn on the bobbin changer power switch. 0996M • Is a standby signal still being input from the bobbin changer? Check the bobbin changer.
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22. TROUBLESHOOTING Error code Possible cause Page • Is the machine connector inside the control box disconnected? Instruction manual Insert the connector securely. • Is the machine head tilted back? Return the machine head to its normal position. 62, 104 Check the operation of the safety switch.
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22. TROUBLESHOOTING Error code Possible cause Page • Is the synchronizer connector inside the control box disconnected? Insert the connector securely. • Problem with synchronizer. Replace the motor. 0982M 1929M • Is detector pin (1) of the bobbin thread detector not retracted correctly? Retract the detector pin (1).
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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)