Janome 4300QDC, Service Manual

Page 1: ...First Edition 19 September 2018 SERVICE MANUAL MODEL 4300QDC...

Page 2: ...Adjustment of Hook Timing 11 Adjustment of Needle Bar Height 12 Clearance between Needle and Tip of Rotary Hook 13 Feed Dog Height 14 Top Tension 15 Stretch Stitch Feed Balance 16 Replacing the Electr...

Page 3: ...le and thread Use a HA x 11 blue tip needle See mechanical adjustment Needle bar height See mechanical adjustment Adjustment of hook timing See mechanical adjustment Clearance between needle and tip o...

Page 4: ...bin thread 1 Bobbin holder is incorrectly threaded 2 Too much thread is wound on the bobbin 3 Lint is stuck inside the bobbin holder 4 Thread quality is too low 5 Thread is jamming around the bobbin h...

Page 5: ...t tension 4 Not enough oil 5 Upper shaft gear is loose Eliminate the backlash Eliminate the looseness See part removal and replacement driving motor DC motor Oil all moving parts Eliminate the loosene...

Page 6: ...anging External Parts Face cover To remove 1 Loosen the setscrew q and lift the face cover to disengage the rib on the inside Remove the face cover w To attach 2 Follow the above procedures in reverse...

Page 7: ...5 Free arm cover To remove 1 Loosen the setscrew q and w Move the free arm cover e to the left Remove the free arm cover To attach Follow the above procedures in reverse Changing External Parts q w e...

Page 8: ...emove the setscrews B w 6 pcs back cover e 4 Remove the setscrews C r 2 pcs 5 Loosen the setscrew t 6 Disconnect all the connectors from the circuit board A NOTE Do not disconnect the connectors by pu...

Page 9: ...7 Changing External Parts Front cover 2 1 Disengage the front cover and rear cover hooks 2 Remove the front cover To attach Follow the above procedures in reverse...

Page 10: ...cover and free arm cover See page 4 and 5 2 Remove the setscrews A q 5 pcs 3 Remove the setscrews B w 6 pcs and back cover 4 Remove the setscrews C e 2 pcs Remove the rear cover To attach 5 Follow th...

Page 11: ...he feed dog below the needle plate Place a block 6 mm thick under the presser foot and lower the presser foot lifter w 3 Loosen the setscrew q Raise the presser foot lifter and tighten the setscrew q...

Page 12: ...0 The clearance between the needle and the edge of the needle hole should be at least 0 2 mm on either side If not adjust as follows 1 Turn the power switch off Remove the face cover See page 4 2 Loos...

Page 13: ...oward you to lower the needle at its lowest position 5 Loosen the hexagonal socket screw w 2 pcs 6 Move the needle bar 3 25 to 3 55 mm from the lowest position 7 Turn the lower shaft gear until the ti...

Page 14: ...ct the pattern left position Set the zigzag width at 0 4 Turn the handwheel toward you until the tip of hook meets the right side of the needle 5 Loosen the hexagonal socket screw q 6 Move the needle...

Page 15: ...thin 0 10 to 0 05 mm at the left and right needle position 5 Tighten the setscrew A 2 pcs 6 Attach the face cover Remove the master needle Attach the bobbin holder and needle pate 7 Check the clearanc...

Page 16: ...highest position 3 Remove the free arm cover 4 Loosen the setscrew q and nut w 5 Adjust the feed dog height by turning the adjusting screw e The highest position of the feed dog should be between 0 80...

Page 17: ...he above limit adjust as follows 1 Set the tension dial 4 2 Remove the cover 3 Lower the presser foot If the top tension is too loose turn the lead screw in the direction A If the top tension is too t...

Page 18: ...w to the left to loosen it Move the gear up A or down B to adjust the feed Do not move the gear right or left when adjusting Start the machine and check the movement of the fabric Adjust the hexagonal...

Page 19: ...cuit board F white w Printed circuit board L2 White e Program Black r Bobbin winding switch Blue t Thread cutter motor white y Touch panel White u Feed motor White i Printed circuit board P black o Sw...

Page 20: ...o the test you want to perform Enter self diagnostic mode then select the step number of the diagnostic test you require by pressing the reverse stitch button To begin Turn on the switch if any of the...

Page 21: ...pressed LCD displays F3 when button 4 is pressed LCD displays 03 When the buttonhole lever is pulled buzzer sounds and LCD displays BH symbol BH symbol Bobbin symbol Press buttons 1 to 4 If the result...

Page 22: ...rect condition press the start stop button to proceed the next step If the result is defective condition press the reverse stitch button to proceed the next step LCD displays 06 Turn the handwheel LCD...

Page 23: ...e foot control is attached Buzzer sounds when the foot control is deeply depressed Buzzer sounds when the foot control is released LCD displays 09 10 DC motor Buzzer sounds at rightmost or leftmost po...

Page 24: ...the result is correct condition press the start stop button to proceed the next step If the result is defective condition press the reverse stitch button to proceed the next step Defective Condition T...

Page 25: ...and fix the defective part The defective part number See page 23 to 25 Steps and items section Turn the power switch off when the self diagnostic test is finished To display the version of the progra...

Page 26: ...m the circuit board A 3 Remove the screws 4pcs and the circuit board A To attach 1 Follow the above procedures in reverse NOTE Do not disconnect the connectors by pulling on cord To disconnect grasp t...

Page 27: ...lt Tighten them with setscrews 2pcs lightly 2 Move the motor up or down to adjust the motor belt tension The belt should deflect 5 mm when applying 200 grams force of load to the middle of the belt Ti...

Page 28: ...the rear cover 2 Remove the setscrews A 3 pcs and the switching regulator 3 Remove the setscrews B 4 pcs To attach 4 Follow the above procedures in reverse Replacing the Electronic Components Switchin...

Page 29: ...n the button hole lever r is lowered Tighten the setscrew To adjust the buttonhole sensor position 4 Attach the buttonhole foot R e 5 Lower the buttonhole lever r to its lowest position and open a 1 6...