Upper Thread Miss-Winding; Work Clamp Is Not Raised; Pulse Motor Stepping Sound Cannot Be Heard - Brother HE-800B Instruction Manual

11. TROUBLESHOOTING

11-22. Upper thread miss-winding

Items with a "*" in the "Page" column should only be handled by a qualified technician.
Cause
Upper thread trimmer
Stitch quality
Work clamp
Underlay
Bar tack

11-23. Work clamp is not raised (1)

...... Pulse motor stepping sound cannot be heard

Items with a "*" in the "Page" column should only be handled by a qualified technician.
Cause
Work clamp lifting
height
Work clamp motor
93
Check
Installation height
Upper thread trimmer
gradual opening timing
Upper thread trimmer
opening timing
Upper thread trimmer
assembly movement
Lateral position of upper
thread trimmer
Upper thread tension
Zigzag width in the zigzag
stitch portion
Uneven material feeding
Underlay is being sewn.
Straight bar tacking
being carried out
Check
Check the work clamp
lifting height setting
Cord connection
Work clamp motor drive
gear
Adjust the upper thread trimmer installation height.
Adjust the timing so that the upper thread trimmer
gradually start opening when the feed mechanism
moves about 1.5 - 2.5 mm.
Adjust so that the cam opens the stop plate properly.
・Polish blade of upper thread trimmer M and upper
thread guide with buffer.
・Check for burrs on the top surface of upper thread
trimmer M.
・Replace the parts.
Adjust the lateral position of the upper thread trimmer.
Approx. 1 mm
Decrease tension to such a degree that it does not
influence stitch quality.
Use parameter number 08 to increase the zigzag width
to such a degree that it does not influence the seam
shape.
・Increase work clamp pressure. (Press material so
that the material is properly stretched.)
・When using knits or woven materials, replace the
parts with the -3 specification parts:
Length feed plate (for specification -3), work clamp
assembly (for knits),
specification -3)
・Use parameter number 47 to reduce the underlay
feed pitch to about 0.5.
・Use parameter number 14 to reduce the underlay
sewing speed.
* If sewing knitted wear, problems may easily occur
with the insertion of the upper thread, so you may
need to process the end of the thread.
is When carrying out straight bar tacking, problems may
easily occur with the insertion of the upper thread, so
you will need to process the end of the thread.
Change the settings of memory switch Nos. 001, 002,
003, 004.
Check if there are any problems with the connection
and contacts of work clamp motor connector P23 on
the main P.C. board.
Check if the drive gear screw is loose.
HE-800B
Remedy
needle plate 1.2
Remedy
Page
68*
69*
69*
*
*
4020Q
26, 27
36
66*
*
(for
39
36
–
Page
56
10*
*