ELNA eXcellence 780 User manual

SERVICE MANUAL
MODEL: eXcellence 780
First Edition: 3 June 2016

INDEX
Changing External Parts
Face cover...........................................................................................................................................1
Top cover.............................................................................................................................................1
Belt cover ............................................................................................................................................2
Machine base......................................................................................................................................3
Base cover ..........................................................................................................................................3
Bed cover ............................................................................................................................................3
Free arm cover................................................................................................................................ 4-5
Front cover ...................................................................................................................................... 6-7
Rear cover....................................................................................................................................... 8-9
Replacing Electronic Components
Printed circuit board A................................................................................................................. 10-11
Printed circuit board F.......................................................................................................................12
Switching power supply unit..............................................................................................................13
Driving motor.....................................................................................................................................14
Thread tension unit ...........................................................................................................................15
Mechanical Adjustment
Feed dog height ................................................................................................................................16
Needle drop position .........................................................................................................................17
Clearance between needle and tip of the rotary hook ................................................................ 18-19
Hook timing .......................................................................................................................................20
Needle bar height..............................................................................................................................21
Backlash between hook drive gear and lower shaft gear..................................................................22
Upper shaft shield plate position.......................................................................................................23
Upper thread tension.........................................................................................................................24
Tension release mechanism..............................................................................................................25
Replacing Needle threader hook.......................................................................................................26
Needle threader hook position ..........................................................................................................27
Thread drawing lever.........................................................................................................................28
Upper feed dog (1) ............................................................................................................................29
Upper feed dog (2) ............................................................................................................................30
Upper feed dog (3) ............................................................................................................................31
Buttonhole lever ................................................................................................................................32
Thread cutter.....................................................................................................................................33
Presser bar lifter position ..................................................................................................................34
Presser foot lifter stopper position (1) ...............................................................................................35
Presser foot lifter stopper position (2) ...............................................................................................36
Automatic presser foot lifter initializing position.................................................................................37
Presser bar height.............................................................................................................................38
Stretch stitch feed balance................................................................................................................39
Needle plate switch ...........................................................................................................................40
Knee lifter..........................................................................................................................................41

1
Changing External Parts
Face cover
To remove:
1. Open the face cover.
Disconnect the connector from the face cover.
Remove the setscrews A.
Remove the face cover.
To attach:
1. Follow the above procedure in reverse.
Setscrew A
Face cover
Top cover
To remove:
1. Raise the carrying handle.
Remove the setscrew B.
Close the carrying handle.
Setscrew B
Top cover
2. Open the top cover.
Remove the setscrews C and D.
3. Raise the carrying handle and remove the top cover.
To attach:
1. Follow the above procedure in reverse.
Carrying handle
Setscrew C Setscrew D
Connector

2
Changing External Parts
Belt cover
To remove:
1. Remove the caps from the belt cover.
Remove the setscrews A and B.
Setscrew A
2. Loosen the setscrew C.
Setscrew B
Setscrew D
Belt cover
Setscrew C
3. Loosen the setscrew D.
Remove the belt cover.
To attach:
1. Follow the above procedure in reverse.

3
Changing External Parts
Machine base
To remove:
1. Remove the setscrews A and B .
2. Remove the machne base.
To attach:
1. Follow the above procedure in reverse.
Setscrew B
Setscrew A
Setscrew A
Setscrew B
Machine base
Base cover
To remove:
1. Remove the extension table.
Remove the setscrews A.
2. Remove the base cover.
To attach:
1. Follow the above procedure in reverse.
Bed cover
To remove:
1. Remove the extension table.
Remove the setscrews C.
2. Remove the bed cover.
To attach:
1. Follow the above procedure in reverse.
Setscrew A
Setscrew A
Setscrew A
Setscrew A
Machine base
Setscrew CSetscrew C Bed cover

4
Free arm cover
To remove:
1.
Remove the machine base and base cover (see page 3).
Press the needle plate release lever to remove the
needle plate.
Changing External Parts
2. Remove the pin.
Remove the bed cover (see page 3).
3. Loosen the setscrew A.
Pin Bed cover
Needle plate
Free arm cover Needle plate release lever
Setscrew A

5
4. Remove the free arm cover from the free arm while
unlocking the hook A (front side of the free arm) and B
(inside of the machine base) from the free arm.
5. Slide the free arm cover to the left.
Remove the free arm cover.
To attach:
1. Follow the above procedure in reverse.
Hook B
Hook A

6
Changing External Parts
Setscrew A Setscrew A Front cover
To remove:
1. Remove the top cover, belt cover, base cover, machine
base and free arm cover (see pages 1-5).
2. Loosen the setscrews A .
Setscrew C 3. Loosen the setscrews B and C.
4. Loosen the setscrew D.
Setscrew B
Setscrew D
(Bottom of the machine)
(Top of the machine)

7
5. Loosen the setscrew E.
Hooks
Setscrew E
6. Unlock the hooks from the front cover.
Remove the connectors from the circuit board A.
Remove the front cover.
To attach:
1. Follow the above procedure in reverse.
Refer to page 7 for locating connector posts.

8
3. Loosen the setscrew A.
Changing External Parts
4. Loosen the setscrew B.
Setscrew A
Setscrew B
Rear cover
To remove:
1. Remove the top cover, mahine base, base cover and
free-arm cover (see pages 1, 3 and 4-5.)
2. Open the face cover.
Disconnect the connector from the face cover.
Close the face cover.
Face cover
Connector A