Brother International RH-981A Instruction Manual - Spanish - Page 88

Lower thread is not cut.

Get Brother International RH-981A PDF manuals and user guides View all Brother International RH-981A manuals
Add to My Manuals
Save this manual to your list of manuals

Page 88 highlights

13. TROUBLESHOOTING Problem Cause Remedy Upper thread is not cut. Knife is blunt. Replace with a new knife. Knife does not move to the full stroke because air pressure is Adjust the air pressure. too weak. Upper thread trimmer knife is not picking up the upper thread. Install the upper thread trimmer knife so that it cuts only one side of the upper thread loop. Lower thread is not cut. Movable knife is not picking up Refer to the remedies given the needle thread because the under "Skipped stitches occur" last stitch is being skipped. in this troubleshooting chart. Movable knife incorrect. position is Adjust the position of the movable knife or the loop spreader. Knife is blunt. Replace with a new knife. Knife does not move to the full stroke because air pressure is Adjust the air pressure. too weak. Movable knife incorrect. position is Adjust the position of the movable knife or the loop spreader. Thread slips out of the Thread nipper spring force is too Adjust the force of the thread needle at the sewing start. weak. nipper spring. Upper thread length is too short after trimming. Install the upper thread trimmer knife so that it cuts only one side of the upper thread loop. Needle and looper adjustment is Adjust the needle bar height or incorrect. the looper and spreader height. Not enough upper thread is Adjust the amount of upper being fed out. thread being fed out. Material cleanly. is not being cut Cutting pressure is too weak. Adjust the cutting pressure so that it is strong enough. Knife and hammer contacting properly. are not Grind the hammer surface. Knife is blunt. Replace with a new knife. Page 63 63 66 80 66, 67 63 63 66, 67 66, 67 66 55 57 63 62 63 RH-981A 81

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
13. TROUBLESHOOTING
RH-981A
81
Problem
Cause
Remedy
Page
Knife is blunt.
Replace with a new knife.
63
Knife does not move to the full
stroke because air pressure is
too weak.
Adjust the air pressure.
63
Upper thread trimmer knife is
not picking up the upper thread.
Install the upper thread trimmer
knife so that it cuts only one side
of the upper thread loop.
66
Movable knife is not picking up
the needle thread because the
last stitch is being skipped.
Refer to the remedies given
under “Skipped stitches occur”
in this troubleshooting chart.
80
Upper thread is not cut.
Movable
knife
position
is
incorrect.
Adjust
the
position
of
the
movable
knife
or
the
loop
spreader.
66, 67
Knife is blunt.
Replace with a new knife.
63
Knife does not move to the full
stroke because air pressure is
too weak.
Adjust the air pressure.
63
Lower thread is not cut.
Movable
knife
position
is
incorrect.
Adjust
the
position
of
the
movable
knife
or
the
loop
spreader.
66, 67
Thread nipper spring force is too
weak.
Adjust the force of the thread
nipper spring.
66, 67
Upper thread length is too short
after trimming.
Install the upper thread trimmer
knife so that it cuts only one side
of the upper thread loop.
66
Needle and looper adjustment is
incorrect.
Adjust the needle bar height or
the looper and spreader height.
55
Thread
slips
out
of
the
needle at the sewing start.
Not enough upper thread is
being fed out.
Adjust the amount of upper
thread being fed out.
57
Cutting pressure is too weak.
Adjust the cutting pressure so
that it is strong enough.
63
Knife and hammer are not
contacting properly.
Grind the hammer surface.
62
Material is not being cut
cleanly.
Knife is blunt.
Replace with a new knife.
63