Service manual model: jw7630
Contents what to do when ......................................................................................................... 1 - 2 service access (1) face cover, top cover ............................................................ 3 service access (2) base, bed cover ...........................
1 condition cause how to fix reference 1. Skipping stitches 1. Needle is not inserted properly. 2. Needle is bent or worn. 3. Incorrectly threaded. 4. Needle or thread are inappropriate for fabric being sewn. 5. Sewing on stretch fabric. 6. Inappropriate needle bar height. 7. Inapppropriate needle t...
2 condition cause how to fix reference 4. Breaking bobbin thread 1. Incorrecitly threaded bobbin holder. 2. Too much thread is around on the bobbin. 3. Lint is stuck inside the bobbin holder. 4. Thread quality is too low. 5. Thread is jamming around the bobbin. Thread bobbin holder correctly. Adjust...
3 cap face cover service access (1) ribs face cover to remove: 1. Remove the cap. 2. Remove the setscrew (a) and remove the face cover. To install: 3. Insert the 2 ribs of the face cover into the rear cover and tighten the setscrew, then attach the cap. Top cover to remove: 1. Remove the face cover....
4 service access (2) base to remove: 1. Remove the 4 setscrew (a) and the 2 setscrew (b), remove the base. To install: 2. Place the part c (concave part in the illustration) between the base and the arm leg. Install the base with the 4 setscrews (a) and the 2 setscrews. Bed cover to remove: 1. Set t...
5 service access (3) free arm cover to remove: 1. Remove setscrew (a) and the needle plate. 2. Remove the bed cover (see page 4). 3. Remove setscrew (b) and the free-arm cover. To install: 4. Follow the above procedure in reverse. Setscrew (a) setscrew (b) needle plate free arm cover.
6 service access (4) belt cover to remove: 1. Remove the setscrews (a), (b), and remove the belt cover. To install: 2. Install the belt cover with the setscrews (a) and (b). Setscrew (a) setscrew (b) belt cover.
7 service access (5) front cover to remove: 1. Remove the top cover and belt cover (see pages 3 and 6). 2. Loosen the setscrews (a), (b), (c), (d) and (e), then remove the setscrew (f). 3. Disconnect connectors from printed circuit board "a". Notes: to disconnect the connectors: grasp the connector ...
8 service access (6) rear cover to remove: 1. Remove the top cover and belt cover (see pages 3 and 6). 2. Loosen the setscrews (a), (b), (c), and (d), then remove the setscrew (e). 3. Remove the rear cover. * to remove the cover, detach the presser foot lifter section first, with the presser foot li...
9 presser bar height and alignment when the presser foot is raised, the clearance between the presser foot and the needle plate should be 6.0 mm. When the presser foot is lowered, the edge of the foot and the feed dog window on the needle plate should be parallel. 1. Remove the face cover and raise ...
10 mechanical adjustment eccentric pin setscrew 3x4 needle plate hole 0.2 mm or more 0.2 mm or more a=b needle drop position set the stitch pattern at " "; the standard needle drop position should be at the center of the needle plate hole. When the needle swings in maximum zigzag width " ", the dist...
11 mechanical adjustment setscrew (a) needle setting groove tip of hook meets right side of needle needle #14 hook race 1.6-2.0 mm upper edge of needle eye hook race unit needle bar height the distance between the upper edge of needle eye and the tip of the hook should be in the range of 1.6-2.0 mm ...
12 lower shaft gear mechanical adjustment needle to hook timing when the machine is set the straight stitch pattern no.2 ( left needle position), the amount of ascending travel of the needle bar from its lowest position to the position where the tip of the hook meets the right side of the needle sho...
13 needle clearance to hook the clearance between the needle and the tip of hook should be -0.1 to +0.05 mm. Preparation: 1. Remove the needle plate, bobbin holder, and bed cover, and replace the needle with the test pin (b). 2. Turn the power switch on, and select pattern " " (simple zigzag). (maxi...
14 mechanical adjustment backlash (between lower shaft gear and hook gear) jog the hook race back and forth to check rotary play. The standard play should be 0.8 mm (0.03") or less when the hook point is within the feed dog width. If play exceeds 0.8 mm, adjust as follows. Adjustment: 1. Remove the ...
15 mechanical adjustment feed dog height the highest position of the feed dog should be between 0.8 to 0.9 mm from the surface of the needle plate when the pressure dial is set at "3" and the presser foot is lowered. 1. Set the pressure dial at "3" and lower the presser foot. 2. Turn on the power sw...
16 mechanical adjustment zigzag synchronization the needle should start swing between 6.3 to 7.5 mm above the surface of the needle plate when the machine is set for zigzag stitching. 1. Remove the front cover (see page 7). 2. Turn on the power switch, select the zigzag stitch and set the machine at...
17 mechanical adjustment tension release mechanism when the presser foot lifter is raised, the tension disk supporter should move approximately 1 mm. 1. Remove the front cover (see page 7). 2. Lower the presser foot lifter, and set the thread tension dial at "9". Then loosen the set screw (a). 3. Wh...
18 mechanical adjustment thread (polyester sewing thread (#50 white)) pull the thread at a speed of approx. 110 mm/sec. In the direction of arrow. Needle thread tension the standard tension should be 75 to 90 grams when the tension dial is set at "4", measured with a #50 white polyester thread being...
19 stretch stitch feed balance when a stretch stitch pattern is sewn with the feed balancing dial position set at the standard setting mark " ", the stitch pattern should look like the one marked with a " " (a=b) in the diagram below. If forward and backward feeding is unbalanced (a>b or a adjustmen...
20 mechanical adjustment threader knob hook needle hole replacing the needle threader cover (with the threader plate attached threader plate supporter (a) fig. 1 vertical adjustment threader position set plate fig. 3 fig. 2 x pin (b) setscrew (d) replacement and adjustment of the needle threader pla...
21 refer to the diagram for locating the connector posts to which each connectors should be connected. Note: to disconnect the connectors: 1. Grasp the connector directly with your fingers and pull. Do not pull the lead wire, as this may damage the contact sleeve inside the connector. 2. When discon...
22 preparation: * turn off the power switch. * shift the bobbin winder spindle to the left. * raise the feed dog. * shift the slide volume to the left. * remove the presser foot and raise the presser foot lifter. * turn the handwheel toward you to raise the needle to its highest position. * connect ...
23 correct results * beep sounds when the buttons are pressed. * led displays " 8.8", and blinks in 1- sec. Intervals. 7- segment led displays "ld" 3 mode leds blink in 1-sec. Intervals. * led indicates "--". * button number is displayed when the button is pressed. * led indicates "ii". (at left pos...
24 correct condition step 06) buttonhole sensor operation defective condition press needle up/down button, led displays "06" for one second. 1. Lower the buttonhole lever. 2. Move the buttonhole lever back and forth. * when the buttonhole lever is pulled, led displays "h". * when the buttonhole leve...
25 * led display is dtfferent from that shown to the left. If led displays "e1", replace the width motor or board "a". When the foot control is not depressed, led should display "f0" to "ff" (hexadecimal value). When the foot control is fully depressed, led should display "05" to "2f". When the cont...
26 step 12) dc motor operation corect condition defective condition the end of test: all of test is finished, turn off the power switch. Press needle up/down button, led indicates "12" for one swcond. * press foot control. * led indicates "dc". * machine runs at the speed set by the speed control le...
27 printed circuit board "f" setscrew setscrew printed circuit board "a" to remove: 1. Remove the front cover (see page 7). 2. Unplug the connectors from the board "a". 3. Remove the 6 screws and remove board "a". Note: to disconnect the connectors: 1. Grasp the connector directly with your fingers ...
28 printed circuit board "f" connector printed circuit board "f" setscrews (2) replacing the slide volume to remove: 1. Remove the front cover unit (see page 7). 2. Unplug the slide volume connector. 3. Remove the four cs ring (a) and remove the side volume. To install: 4. To install the slide volum...
29 replacing dc motor and adjusting motor belt tension pressure 300g belt tension: 7~9 mm setscrews (2) dc motor belt to remove: 1. Remove the front and rear covers (see page 7 and 8). 2. Remove the two setscrews, then remove the dc motor and belt. To install: 3. Lightly tighten the two screws. 4. P...
30 setscrews (4) printed circuit board "a" printed circuit board "a" case replacing the fuses fuse holder fuse f2. Ac250v 3.15a f3. Ac250v 2.5a f1. Ac250v 2.5a fuse no. F1, f3 f2 part no. 000-144-605 000-182-904 replacing the fuses to remove: 1. Remove the front cover (see page 7). 2. Remove the fou...
31 setscrew (b) machine socket replacing machine socket (unit) setscrew (b) replacing the machine socket to remove: 1. Remove the front and rear cover (see page 7 and 8). 2. Remove the two setscrews and remove the machine socket. To install: 3. To install the machine socket, follow the above procedu...
32 replacing the transformer to remove: 1. Remove the front cover (see page 7). 2. Remove the two setscrews and remove the transformer. Cut off the binder. To install: 3. To install the transformer, follow the above procedure in reverse. Note place the rear end of the transformer on the transformer ...
33 replacing the zigzag width motor to remove: 1. Remove the front and rear cover (see page 7 and 8). 2. Remove the two zigzag rod setscrews (b). 3. Remove the two setscrews (c) and remove the zigzag width motor. To install: 4. To install the zigzag width motor, follow the above procedure in reverse...
34 replacing the feed motor to remove: 1. Remove the front cover and rear covers (see page 7and 8). 2. Remove the snap ring (e-3). 3. Remove the two setscrews and remove the feed motor. To install: 4. To install the feed motor, follow the above procedure in reverse. Note adjust the stretch stitch pa...
35 adjusting buttonhole lever position to adjust the buttonhole lever guide: 1. Set the machine in buttonhole sensor adjusting mode. (see below. The led should display "h" or "l".) 2. Remove the face cover and loosen setscrew (a). 3. Lower the buttonhole lever. Loosen the setscrew and position the b...
36 to adjust the bobbin winding switch 1. Remove the front cover (see page 7). 2. Set the bobbin winder arm in the sewing position and loosen the setscrew. Adjust the clearance between the bobbin winder arm and the switch fixing plate to o.7 to 1.3 mm. 3. Tighten the setscrew. 4. Install the front c...
37 factory lubricated parts will provide years of household sewing without routine oiling, but you should still check for possible lubrication needs whenever servicing machines. Oil: use good quality sewing machine oil at the points (a, b, c, d, e, f, g, h, i, j & k) indicated by the black arrows. G...