1)Imperfect Cutter Function (Imperfect Material Cutting) - Brother LH4-B800E Service Manual

5-13. (1)Imperfect cutter function (imperfect material cutting)

Cause
Cutter Cutter position
Cutter blade
Cutter Check for a
solenoid disconnected cord.
Cutter power Memory switches
Solenoid Nut
stopper
Cutter sensor position
(2) Cutter does not return
Cause
Cutter Cutter blade
Sticks in Needle plate
material
(3) Cutter and upper thread scissors touch.
Cause
Upper thread Is the cam opening the
scissors stop plate?
Check
Adjust cutter vertical
height
If the blade is worn or
chipped, sharpen it or
replace it.
Connect the cords.
Increase the setting for
memory switch No. 00.
(cutter cutting force).
Check for a loose nut.
Adjust the cutter
sensor position.
Check for a loose
mounting screw.
Check
If the blade is worn or
chipped, sharpen it or
replace it.
Replace with the
special needle plate.
Check
If the feed mechanism
operates when the cam
has not opened the
stop plate, the cutter
will bump against the
upper thread scissors.
Adjust the cam
position.
Solution
Install the cutter so that its edge is
aligned with the top of the needle
plate.
Aligned
Replace with the special needle
plate.
Increase the setting value for
materials that are heavy or difficult
to cut.
Tighten securely.
Solution
This needle plate uses the elasticity
of rubber to prevent the knife from
getting stuck and not returning. It
also helps to keep the knife blade
sharp.
Solution
NG
LH4-B800E
5. Troubleshooting guide
page
4-11
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(Instruction)
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(Instruction)
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4-9
page
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(Instruction)
4-11
page
4-18
O.K.
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