JUKI HZL-NX7, Service Manual

Page 1: ...SERVICE MANUAL HZL NX7 COMPUTER SEWING MACHINE ...

Page 2: ... shaft coupling and the lateral timing of the hook driving shaft 19 6 8 Timing between the needle and the hook 20 6 9 Clearance between the needle and the blade point of hook 21 6 10 Position of the hook rotation stopper plate 22 6 11 Adjusting the bobbin thread tension 22 6 12 Adjusting the needle thread tension 23 6 13 Vertical position of the needle threading hook 24 6 14 Adjusting the auxiliar...

Page 3: ...ol When the motor shaft of the sewing machine is accidentally constrained the power supply to the motor is stopped within two seconds When the motor is overheated the built in thermal switch stops the power to the motor Note that the machine can be restarted once the motor spontaneously cools down 5 Stop position Upon finishing sewing the machine stops according to the preset needle stop position ...

Page 4: ... the preset amount of feed Other patterns Zero feed is inserted and one each stitch is sewn in the normal and reverse directions at the beginning and end the reverse switch is turned ON of sewing Amount of feed Fixed at 0 4 mm 13 Buttonholing Auto return type full automatic buttonholing Buttonholing size detection 14 Save and call patterns Selected patterns and pattern settings can be stored in me...

Page 5: ...tch 6 2 Adjusting the needle entry point Faulty material feed 6 3 Feed dog height 6 16 Adjusting the presser bar height 6 22 Position of the automatic DF motor Contact between needle and throat plate or hook 6 2 Adjusting the needle entry point 6 5 Feed timing 6 8 Timing between the needle and the hook Faulty pattern shape 6 3 Feed dog height 6 18 Longitudinal feed Faulty automatic thread trimming...

Page 6: ...og Throat plate Hook cover Bobbin winding shaft Hook cover release button Presser foot holder Thread trimming button Wide table Thread cutter Lock stitch but ton Speed controller Needle up down button Knee lifting lever hole Light under arm Reverse stitch button Presser foot auto lift button Hand wheel pulley Power switch Machine socket inlet Foot controller jack USB insertion slot Cloth puller to...

Page 7: ... from the face cover Then remove the face cover Fitting a flat blade screwdriver T shape in the nearest slot in the throat plate push up the throat plate with the screwdriver until it comes off Then remove the throat plate 4 Disassembling the machine covers 1 Top cover 2 Face cover 3 Throat plate T shape ...

Page 8: ...tor Remove the spool cover from the main unit of the machine paying attention to the base tension 4 Spool cover Base tension Remove setscrews to of the bottom cover B on the handwheel side to detach the bottom cover B Remove setscrews to of the bottom cover A on the frame side Draw out the bottom cover A in the direction of the arrow while pushing up the tip of the cover 5 Bottom cover Junction co...

Page 9: ...in the direction of the arrow 6 Bottom cover of the free arm Remove free arm upper cover setscrews and Pull out the upper cover of the free arm in the direction of the arrow 7 Upper cover of the free arm Remove setscrews and from the face plate cover Remove the face plate cover 8 Face plate cover ...

Page 10: ...C and D of the front panel and rear panel while pushing down the front panel Opening the right side of the front panel in the direction of the arrow tap E section with your hand to remove hook F located at the bed surface Lastly remove hook G located at the lower side of the machine jaw If needed remove the switch slide VR connector CN17 and panel I F con nector CN19 from the main PCB Then remove ...

Page 11: ... 9 10 Rear panel Remove setscrews to from the rear panel Remove the rear panel with the presser foot lifting lever raised Main PCB Panel I F CN19 SW slide volume PCB CN17 LED1 CN208 Panel PCB ...

Page 12: ...ND 12 3 3V CN18 Reserve Unused 2 GND 4 GND CN19 Panel I F cable asm 1 5V 2 5V 3 GND 4 GND 5 RXD 6 TXD 7 S STATE 8 UDET 9 Reset 10 5V 11 5V 12 Panel detection signal 13 GND 14 GND 15 NC CN17 CN6 CN31 CN3 CN15 CN13 CN20 CN5 CN14 CN4 CN29 CN25 CN30 CN9 CN19 CN27 CN28 CN26 CN16 CN2 CN18 CN34 CN1 Connec tor No Destination Termi nal No CN1 Debug Unused 1 3 3V 6 GND CN2 Flash memory interface 1 5V 5 GND ...

Page 13: ...otor 1 Bobbin winder switch 2 GND 3 Bobbin winder motor 29V 4 Bobbin winder motor CN27 Controller socket 1 GND 2 Controller CN28 Power supply relay lead wire 1 29V 2 29V 3 NC 4 GND 5 GND CN29 Motor filter PCB 1 Main motor 29V 2 Main motor 3 FG Connec tor No Destination Termi nal No CN30 Knee lifter slide VR PCB 1 3 3V 2 Knee lifter position detec tion signal 3 GND CN31 Presser foot lifting switch ...

Page 14: ... 7 36 LCD signal 37 3 3V 38 GND 39 Backlight 40 Backlight CN204 USB 1 5V 2 3 USB signal 4 GND Connec tor No Destination Terminal No CN205 Reserve Unused 1 5V 5 GND CN206 Write 10 GND 11 3 3V 12 14 GND CN207 For external power supply 1 5V 2 GND CN208 On hand LED PCB 1 1 5V CN209 On hand LED PCB 2 1 5V CN210 Under arm LED PCB 1 5V CN211 Under arm LED PCB 1 5V CN212 Reserve Unused 5 8 22 24 3 3V 16 1...

Page 15: ...B Touch panel Main PCB Motor filter PCB BLACK WHITE 6P 6P Top feed STM 4P 4P CN1 Top feed detection PCB 4P Flash memory interface CN4 CN14 CN5 GREEN CN17 SW slide volume PCB CN204 USB Write CN206 CN207 For external power supply GREEN Thread trimmer origin detection SW CN30 Knee lifter slide VR PCB BLACK 12P 3P 15P CN212 Unused Presser foot lifting switch cable asm Thread tension STM Presser lifter...

Page 16: ...e needle does not slip off from the connecting stud 5 Place the metal plate on the throat plate Move the needle bar up and down by hand to adjust so that the cut surface of the gauge needle aligns with the top surface of the metal plate Then turn the needle bar by two degrees of an angle as illustrated in the sketch below 6 Temporarily tighten needle bar connecting stud setscrew and reconfirm that...

Page 17: ...n Choose center needle position 2 Assemble a needle 14 into the needle bar loosen the setscrew in the eccentric collar and adjust the feed bar eccentric collar so that the needle meets the center of the needle slot in the throat plate when it reach es the top surface of the throat plate by turning the hand wheel Setscrew Feed bar eccentric collar ...

Page 18: ...g 2 To adjust the rear end of the feed dog loosen the setscrew and adjust the height of the feed dog with a flatblade screwdriver or the like by inserting the screwdriver into the adjustment hole After the adjustment tighten the setscrew Fig 3 5 Adjust the feed dog height both at its front and rear ends so that it juts out from the top surface of the throat plate by 1 0 0 1 mm Fig 4 1 0 0 1 mm 1 0...

Page 19: ...en the setscrew 6 5 Feed timing After checking the feed dog height and the needle bar height carry out adjustment of the feed timing Adjustment procedure 1 Assemble a HA 1 needle 14 into the needle bar 2 Loosen setscrew No 2 in the hook driving shaft pulley 3 Loosen setscrew No 1 in the hook driving shaft pulley Adjust the pulley so that the lower end of the needle eye in the descending needle 14 ...

Page 20: ...he lowest position Then tighten the setscrew of the collar Fig 2 Caution After tightening the setscrew check to make sure that the shield does not come in contact with the sensor If the former comes in contact with the latter loosen the sensor setscrew and adjust the lateral position of the sensor Fig 1 Fig 2 When the needle bar is brought to its lower dead point Turn the marking hole directly dow...

Page 21: ... opposite to each other Fig 3 3 At the center of the right and left hook driving shafts tighten the coupling setscrew so that there is no backlash in the thrust direction of the coupling Fig 4 Caution When tightening the setscrew take care not to allow the coupling to move out of alignment from the flat section of the shaft In addition carefully confirm the timing of the right and left hook drivin...

Page 22: ...he right needle position Move the hook driving gear in the rotational direc tion to adjust distance D of 3 1 to 3 3 mm is provided between the tip of blade point of the hook and the upper end of the needle eye when the needle bar is lifted by 1 6 mm from the lowest dead point by turning the hand wheel by hand At this time the backlash between the hook driving gear and the gear on the hook side may...

Page 23: ... tighten screw 1 3 Slightly loosen setscrew Adjust the lateral balance of the needle bar by slightly moving right left adjust er while carefully listening to the noise produced when the needle deviates at the right and left needle entry points Then securely tighten setscrew 4 Additionally turn shaft and securely tighten screw at the position where the needle does not deviate 5 Lightly tap P sectio...

Page 24: ...e hook race surface and the bobbin case holder may be stained with dirt oil or grease Wipe them off with an alcohol soaked cloth where necessary If those parts are left stained chattering or thread slip off noise of the bobbin case holder can occur 6 11 Adjusting the bobbin thread tension Remove the throat plate Adjustment procedure 1 Position the bobbin case holder and a tension gauge as illustra...

Page 25: ...Select pattern No 001 straight stitch Set the thread tension to the default value 0 0 2 Lift the presser foot Prepare polyester thread Schappe Spun 60 and a tension gauge Pass the thread through the base tension pre tension and tension disk 4 Lower the presser foot Turn the adjusting nut to adjust the tension so that the tension gauge gives a read ing of 0 49 to 0 59 N ...

Page 26: ...4 Fit a hexagonal wrench on the needle bar guide setscrew to loosen it slightly If the needle threading hook position is too low Move the needle bar guide upward and temporarily tighten the setscrew If the needle threading hook position is too high Move the needle bar guide downward and temporarily tighten the setscrew Adjust the needle threading hook carefully checking its position with respect t...

Page 27: ...t so that the distance shown in the enlarged partial view is ob tained 2 Tighten the locknut to fix the adjusting nut Caution If the thread does not enter the guide slit of the needle threading hook when threading the nee dle check the distance and adjust it correctly Adjusting nut Locknut Enlarged partial view Guide slit 6 7 0 1 mm ...

Page 28: ...e the face cover Adjustment procedure 1 Assemble the standard presser foot in the presser foot holder Raise the presser foot lifting lever 2 Loosen the setscrew of the presser bar position bracket Adjust the distance from the top surface of the throat plate to the bottom face of the standard presser foot to 6 0 3 mm At this time check the direction of the presser bar so that the standard presser f...

Page 29: ...ulley 2 Adjust the motor bracket so that the belt deflection amount becomes 6 1 mm when pressing the center of the belt with a force of 0 98 N After completion of adjustment tighten the setscrew in the motor bracket Motor pulley Motor shaft pulley Motor bracket Setscrew of the motor bracket Setscrew of the motor bracket 0 98 N 6 1 mm ...

Page 30: ...or more continuously in repetition Adjust with so that the bottom end seam of the inner left row of a turn back section of the darning pattern is on a line with the bottom end seam of the right row rough indication of error 0 1 mm third darning pattern seam is on a line as illustrated in the figure and confirm with 1 mm 1 mm Direction of adjustment of lengthwise feed In the case the lower end of t...

Page 31: ...ront panel Adjustment procedure 1 Loosen the motor bracket setscrew 2 Remove the backlash from the presser foot pressure lever gear and the presser foot lifting lever intermedi ate gear reduction gear Then tighten the setscrew Presser foot pressure lever gear Setscrew Presser foot lifting lever intermediate gear reduction gear ...

Page 32: ...til it sinks under the throat plate 3 Push down the presser foot holder until the sole of the basic presser foot comes in contact with the throat plate 4 In the aforementioned state press 5 Press to return the screen to the selection screen under the Service mode 7 Lift the presser foot with the presser foot lifting lever Then lower the basic presser foot with a 12 mm spacer placed under it Carefu...

Page 33: ... the connector of the thread trimming motor 3 Remove two setscrews of the thread trimmer unit Detach the thread trimmer unit Micro switch Thread trimmer unit Setscrews of the thread trimmer unit Micro switch setscrew Thread trimming motor Parallel Moving knife How to attach the thread trimmer unit Reversing the removal procedure attach the thread trimmer unit Caution Attach the thread trimmer unit...

Page 34: ...he rear end of the moving knife and the end of groove in the mechanism base Then tighten the setscrew 2 Check to make sure that the aforementioned clearance becomes 0 3 mm to 1 mm or less when the thread trimmer operates and stops Micro switch Thread trimmer unit At the time of adjustment After the thread trimmer has operated 0 5 mm 0 3 to 1 mm Clearance Setscrew ...

Page 35: ... thread trimmer unit 1 Remove the cover of the top feed dog Fig 1 2 Remove the slide body spring Fig 2 3 Remove two setscrews Detach the top feed dog Fig 3 Fig 1 Fig 2 Fig 3 Fig 4 How to attach the thread trimmer unit 1 Attach the top feed dog with two setscrews At this time temporarily tighten the setscrews 2 Attach the slide body spring 3 Place the top feed dog at its predetermined position Secu...

Page 36: ... Fig 2 turn the handwheel to check that the DF operating part is brought to the position left side of the groove as shown in Fig 3 3 Loosen two setscrews of the DF motor Adjust the lateral position of DF motor Then tighten set screws to secure the DF motor At this time adjust the position of DF driving part by shifting it in the direction of the arrow so that its tip slightly comes in contact with...

Page 37: ...gzag width at 7 0 mm The fagoting pattern can be sewn A Darning Select the darning pattern Darning pattern can be sewn with the initial value Refer to the longitu dinal feed P28 6 18 Zig Zag Select the zigzag pattern Zigzag pattern can be sewn with the initial value A Kikkou Select the Kikkou pattern Kikkou pattern can be sewn with the initial value A Overcasting Adjust the needle entry point for ...

Page 38: ...e range of scaling factor is 1 00 to 1 80 Default is 1 40 Adjustment is made in increments of 0 05 B 0mm Setting Set the 0 zero mm position of the auto lifter Refer to the Adjust ing the height of the auto lifter P30 6 19 2 12mm Setting Set the 12 mm position of the auto lifter Refer to the Adjust ing the height of the auto lifter P30 6 19 2 Upper Feed Feed amount 0 zero of the top feed is adjuste...

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Page 40: ...2018 05 2 11 1 TSURUMAKI TAMA SHI TOKYO 206 8551 JAPAN PHONE 81 42 357 2341 FAX 81 42 357 2380 http www juki com Copyright C 2018 JUKI CORPORATION All rights reserved throughout the world 40208460 ...