Contents Directions for use ................................4 ESD.......................................4 Service tools..................................5 Settings....................................6 Settings - Quick reference..............................7 1. Belt tension -drive belt ...............................10 2. Belt tension -motor belt .............................10 3. The play of the hook gear ............................11 4. Setting the hook in relation to the feeding eccentric (After feeding)..............12 5.
Directions for use These service instructions are intended to be used by service workshop personnel, or by salesmen who carry out servicing their own districts. They assume a thorough knowledge of the handling of precision appliances and accessibility to service tools. The manual is divided into two sections and covers all service operations and checks which should be carried out when making a complete overhaul of a sewing machine.
Service tools A reasonable requirement in a domestic sewing machine is that it should able to sew all types of fabrics used in the home. The settings made when assembling and sewing-in the machines are those most suited to give the best results in the majority of fabrics and fabric combinations.
Settings - Quick refrance Settings - Quick reference 1. Belt tension, drive belt The belt tension shall be adjusted by turning the eccentric bearing (B) 2. Belt tension, motor belt The belt tension spring (A) should normally be positioned in middle slot on the belt tension device.
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Settings - Quick refrance 10. Setting the needle in centre position The needle should always get to the centre position, when the main switch is turned. 11. The needle bar height When the needle bar is in its lower turning position the distance between the upper end of the needle and the surface (B) of the hook ring should be 28.95 (+ 0.2 mm).
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Settings - Quick refrance 17. Pivot height When the presser foot ”R” is in its ”Pivot” position the distance between the lower side of presser foot ”R” and the needle plate should be 1.50 mm +/-0.20 1,50 mm +/-0,20 mm 18 and 19.
Settings 1. Belt tension -drive belt 1. Remove rear cover and front cover. 2. Loosen the two screws (A) of the bearing clamps. NOTE! The hole (C) should always be on the front half. 2. Belt tension -motor belt 1. Remove rear cover. 2.
Settings 3. The play of the hook gear It is impossible to obtain an equally large play in one rotation of the cog wheel, but it should be as small as possible at the tightest spot during the revolution. Check 1.
Settings 4. Setting the hook in relation to the feeding eccentric (After feeding) Check 1. The needle shall be in its centre position, straight stitching. 2. Set the tip of hook (A) so is centred behind the needle, the of the worm gear (C) should now be positio- Note! The position of the pin shall be 1.5 mm from the top of the frame opening.
Settings 5. The gap between the needle and the hook Check 1. Set the machine on straight stitching. 2. Insert a new needle size 90 universal in the machine. 3. Rotate hand wheel until the tip of the hook arrives behind the needle. 4.
Settings 6. Setting the needle plate (the hook cover) in relation to the needle in the feeding direction. Check 1. Insert a new needle size 90 universal in the machine. 2. In the feeding direction the needle should descend right into the middle of the needle hole of the needle plate.
Settings 7. Setting the feed dog in relation to the needle plate Check 1. Sideways the feed dog should be symmetrically set in relation to the needle plate slot. Adjustment 1. Loosen the 2 screws (A) of the feeding unit. 2.
Settings 8. The height of the hook The height is checked between the bobbin case and the case holder. Check + 0.1 The distance between the bobbin case and the case holder should be 0.5 -0,05 The check is carried out at the tightest spot between the bobbin case and the case holder. Adjustment 1.
Settings 9. Feed dog height Check 1. Bring the feed dog to its highest position. 2. The top of the feed dog should be 0.9-1.1 mm above the needle plate. Check with setting gauge 413 12 73-01 Adjustment 1. Bring the feed dog to its highest position. 2.
Settings 10.Setting the needle in centre position Check 1 1. Insert a new needle size 90 universal in the machine. 2.The needle should always go its to the centre position, when the machine is turned on repeatedly. Check 2 - using Service program 1.
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Settings Adjustment NOTE! To set the Centre position, the covers must be removed. The front cover should be used as a service panel and should stand on the side of the machine and the cables between the cover and pc board must be connected. 1.
Settings 11.The needle bar height Check 1. The needle shall be in its centre position, straight stitching. 2. Bring the needle bar to its lower turning position. 3. The gap between the upper end of the needle and the surface (B) of the hook ring should be 28.95 (+ 0.2 mm).
Settings 12.The timing of the hook in relation to the needle Check - Set a new needle size 90 universal into the machine. - Remove the needle plate, bobbin case holder and the bobbin case. - Set machine on straight stitching. - As the needle is moving upwards, the tip of the hook should pass behind the centre of the needle, when the needle is 2.5 mm above its lower turning position.
Settings 13.Needle threader stop Check The distance between the Cross head and the needle threader stop should be 1.5 mm. Adjustment 1. Loosen screw (A) and move the needle threader stop until the correct measure is obtained. 2. Tighten the screw. 1.5 mm 104 72 79-26...
Settings 14.Threading device Check 1. Insert a new # 70 needle. 2. Bring the needle bar to its highest turning position. 3. The threader hook shall go smoothly into the needles eye. See Fig 1 and Fig 2. Adjustment 1. Loosen the two screws (A) on the back of the threader head (B). 2.
Settings 15.Presser foot parallelism to the feed dog Check The presser foot (A) should be parallel to the feed dog (B). Adjustment 1. Remove the Thread tension unit. 2. Loosen screw (C) and turn the presser foot until it is parallel to the feed dog. 3.
Settings 17.Pivot height Check 1. When the presser foot “R” is in its “Pivot” position the distance between the lower side of presser foot “R” and the needle plate should be 1.50 mm +/-0.20 mm. Adjustment 1. Mount the presser foot”R” on the machine. 2.
Settings 18.Stitch length balance basic setting Check 1 The feed dog should after turning the machine on and off several times always reach such a position that 2.5 mm straight stitching will be obtained. Check 2 1. Go to the service program. 2.
Settings 19. Stitch length balance Check Both columns of the buttonhole shall be of the same density. The darning stitch shall look according to illustration. ( Use service program menu 3 press key nr. 9 ) 0-3 mm Fine adjustment 1.
Settings 20.Lower thread tension (thread tension of the bobbin case) Check 1. Insert a full bobbin into the bobbin case. 2. The thread tension spring of the bobbin case shall give a resistance of 12 - 20 g when pulling the thread slowly, using normal polyester thread.
Settings 21.Thread tension releaser 830 850 Check 1. Set the tension index dial to 9 2. Set the presser foot to its highest position, use the function button presserfoot up. 3. The tension releaser (C) should now have opened the discs, and the tension pin (A) should be against the releaser lever (B) and no play between them.
Settings 22a.Upper thread tension 830 850 Check When the thread tension dial is set at 5, a correct take-up should be obtained at straight stitching and zig-zag using normal cotton fabrics and polyester thread. Adjustment 1. Check so the setting “21. Thread tension Releaser” is correctly set. 2.
22b. Upper thread tension 870 The three setting points create a "tension curve" in the software, we want this curve to be as linear as pos- sible. The settingpoints does NOT effect each other, however they effect the curve BETWEEN each other. Check A correct take-up should be obtained at straight stitching, zig-zag, button hole and satin stitches using nor- mal cotton fabrics and polyester thread.
Settings 23.Setting the thread take-up spring Check The thread take-up spring (A) should have completed its movement when the the needle eye reaches the fabric. The check has to be carried out at 2.5 mm straight stitching and using normal cotton fabrics and polyester thread.
Settings 24.Disconnection when winding the bobbin Check When winding up the lower thread onto the bobbin the machine should stop when there is a min. of 1 mm between the edge of the bobbin and the thread. Adjustment 1.Loosen the Screw. 2.
Service Program Service program Sapphire In order to facilitate the checking and setting of the different functions of the machine there is a service program. Press Handling Get into the service program of the machine by pressing the Minus stitch lengths and Mirror side to side keys while the machine is turned on.
Service Program Functions of the service menu 1 - Step motors To come to Functions Menu 1. 1. Get into the service program of the machine by pressing the Minus stitch lengths and Mirror side to side keys while the machine is turned on. 2.
Service Program Functions of the service menu 2 - Display and Sensor To come to Functions Menu 2. 1. Get into the service program of the machine by pressing the Minus stitch lengths and Mirror side to side keys while the machine is turned on. 2.
Service Program Functions of the service menu 3 - Test patterns To come to Functions Menu 3. 1. Get into the service program of the machine by pressing the Minus stitch lengths and Mirror side to side keys while the machine is turned on. 2.
Service Program Functions of the service menu 4 - Info and Test patterns To come to Functions Menu 4, 1. Get into the service program of the machine by pressing the Minus stitch lengths and Mirror side to side keys while the machine is turned on.
Service Program Functions of the service menu 5 - Key Board Test To come to Functions Menu 5, 1. Get into the service program of the machine by pressing the Minus stitch lengths and Mirror side to side keys while the machine is turned on. 2.
Covers Front Lid 1. Raise the lid up. 2. Take the left lid ending and cautiously push it away from the back covers left pin. Rear cover 1. Remove the six Torx 10 screws (A) on the back cover. 2. Remove the two Torx 20 screws (C), located under the handle, on the back cover. 3.
Covers Front cover Dismantling 1. Remove the rear covers. 2. Remove the two Torx 20 screws (B) in the middle from behind. 3. Remove the Torx 10 screw (E) beside the tension unit from behind. 4. Lay the machine down, front facing up. 5.
Dismantling and mounting Base Plate FOR SAFTEY REASONS ALWAYS DISCONNECT THE POWER CORD FROM THE MACHI- NE BEFORE REMOVING THE POWER SUPPLY. Dismantling 1. Remove the 2 screws for the back cover. 2. Remove the 2 screws for front cover. 3.
Dismantling and mounting Power supply FOR SAFTEY REASONS ALWAYS DISCONNECT THE POWER CORD FROM THE MACHI- NE BEFORE REMOVING THE POWER SUPPLY. Dismantling 1. Remove rear cover. 2. Loosen the two screws (A) of the powersupply from below in the base plate. 3.
Dismantling and mounting Circuit board - Circuit diagram Sapphire 850/830 FOR SAFTEY REASONS ALWAYS DISCONNECT THE POWER CORD FROM THE MACHI- NE BEFORE REMOVING THE CIRCUIT BOARD AND MAKE SURE TO USE WRIST BAND AND ESD MAT. ATTENTION! It is of the utmost importance that precautions are being taken in order to avoid damage of the electronics by electro static discharges (ESD).
Circuit board - Circuit diagram Sapphire 870 FOR SAFTEY REASONS ALWAYS DISCONNECT THE POWER CORD FROM THE MACHI- NE BEFORE REMOVING THE CIRCUIT BOARD AND MAKE SURE TO USE WRIST BAND AND ESD MAT. ATTENTION! It is of the utmost importance that precautions are being taken in order to avoid damage of the electronics by electro static discharges (ESD).
Tension unit Dismantling 1. Remove rear cover and front cover. 2. Place the needle bar in its lowest position using the hand wheel. 3. Remove the cable from PC-board and its fastening points (Only 870). 4. Remove two torx 20 screws one from the front and one from the back (A). 5.
Tension unit - Replacement of the tension discs 830/850 Dismantling 1. Remove back cover and front cover. 2. Remove tension unit. 5. Remove torx 10 screw (B) and loosen the tension wheel spring (A). 6. Put the tension unit on a stand with the discs down. 7.
Tension unit - Replacement of the tension discs 870 Dismantling 1. Remove back cover and front cover. 2. Remove tension unit. 5. Remove torx 10 screw (B) and loosen the tension wheel spring (A). 6. Put the tension unit on a stand with the discs down. 7.
Tension unit - Replacement of the Stepmotor 870 Dismantling 1. Remove back cover and front cover. 2. Remove the cable from its fastening points and the PC-board. 3. Lock the springloaded cog wheel (A) by putting a needle through its hole. 4.
Dismantling and mounting Sewing head Dismantling 1. Remove rear cover and front cover. 2. Remove the thread tension unit. 3. Remove the presser foot holder and needle. 4. Disconnect the cable from the PC-board. 5. Loosen the 2.5 mm Allen key screw (B) and remove both the wedge (G) and the screw(B) by pushing them down.
Dismantling and mounting Step motor of the needle Dismantling NOTE! The sewing head should be in the machine when changing the step motor of the needle. 1. Remove rear cover and the front cover. 2. Disconnect the step motor cable from the sewing heads connecting board. 3.
Dismantling and mounting Step motor of the Presser bar Dismantling NOTE! The sewing head can be in the machine when changing the step motor of the presser bar. 1. Remove rear cover and front cover. 2. Disconnect the step motor cable from the sewing heads connecting board. 3.
Dismantling and mounting Presser bar bushing Dismantling NOTE! The sewing head must be removed from the machine when replacing the bushing of the presser bar. 1. Remove the rear cover and the front cover. 2. Remove the tension unit. 3. Remove the sewing head from the machine. 4.
Dismantling and mounting Needle bar bushing Dismantling NOTE! The sewing head must be removed of the machine when replacing the bushing of the needle bar. 1. Remove the rear covers and the front cover. 2. Remove the tension unit. 3. Remove the sewing head from the machine. 4.
Dismantling and mounting Arm shaft. FOR SAFTEY REASONS ALWAYS DISCONNECT THE POWER CORD FROM THE MACHI- NE BEFORE REMOVING THE CIRCUIT BOARD AND MAKE SURE TO USE WRIST BAND AND ESD MAT. Dismantling 1. Remove the rear cover and the front cover. 2.
Dismantling and mounting Hook cover compl. 830 850 Dismantling 1. Remove the rear cover and the front cover. 2. Raise the presser bar to its highest position. 3. Remove the needle. 4. Remove the presser foot holder. 5. Remove the needle plate by placing a screw driver at (A) and snap it off. 6.
Hook cover compl. 870 Dismantling 1. Remove the rear cover and the front cover. 2. Remove the powersupply. 3. Remove the screw (C). Remove and cut the ziptie. 4. Remove the cable bobbin sensor from the PC-board and its fasteningpoints. 5.
Replace thread cutter knife 870 1. Remove needle plate. 2. Enter the servicemenu 2, key no 4. 3. Press "+" stitchwith twice to go to cut sequence part 2. 3. Turn the knife holder (B) to straight up position and remove the knife holder by pulling it towards the back of the machine.
Dismantling and mounting Hook complete Dismantling 1. Remove rear cover and front cover. 2. Remove the hook cover. 3. Loosen the 2mm Allen screw (B) 4. Rotate the hook upwards a bit, then grip the dust cover, tilt the hook towards the feed dog and remove both parts out of the machine.
Dismantling and mounting Feeding unit step motor Dismantling 1. Remove rear cover and front cover. 2. Remove the base plate. 3. Remove hook cover 4. Disconnect the Step motor cable from the PC Board and bring it out to the back side. 5.
Dismantling and mounting Feeding unit Dismantling 1. Remove rear and front covers. 2. Remove the hook cover. 3. Remove the hook complete. 4. Remove the baseplate. 5. Remove the feeding step motor. 6. Remove the two screws (B). 7. Un-hook the spring from the casting, located on the left side of the feed unit. 8.
Dismantling and mounting Lower Shaft FOR SAFTEY REASONS ALWAYS DISCONNECT THE POWER CORD FROM THE MACHI- NE BEFORE REMOVING THE CIRCUIT BOARD AND MAKE SURE TO USE WRIST BAND AND ESD MAT. Dismantling 1. Remove rear cover and front cover. 2.
Dismantling and mounting Bobbin winding device Needle and feeding movement should be disengaged when the ”bobbin shaft with its rubber ring” is pushed against the ring , and engaged when it is pushed back. Dismantling 1. Remove rear covers and front cover. 2.
Threadcutting unit Dismantling 1. Remove rear cover. 2. Remove front cover. 3. Remove power supply. 4. Remove cables: Thread cut, Bobbin sensor and Cut sensor from the PC-board, and release them from their fastening points. 5. Remove the two torx 20 screws (A) holding the stepper motor. 6.
Remove Thread tension cover Dismantling 1. Remove back cover. 2. Remove front cover. 3. Remove cable from PCboard in front cover. 4. Remove two torx 10 screws from the back (A, B). 5. Remove the thread tension cover (C). Mounting 1.