147
PROBLEM
TIP or PAGE
REMEDY
PROBABLE CAUSE
Short upper thread
after trimming due to
separation failure.
Thread pulls out
before it is cut.
Confirm correct fuse size
and voltage.
Area to check for damage.
If the lower thread is too
short when the trim is made,
the first stitch after the trim
will not form.
Replace the F2 fuse on the
power board first. Then the
F3.
Replace the connection on
the cutting solenoid.
Replace the solenoid.
Replace the power board.
Adjust the upper thread
tension.
Remove the damage on the
movable blade using fine
sandpaper or crocus cloth.
Adjust or replace the
tension spring of the bobbin
case. Remove any dirt or
foreign materials in the
thread guide of the bobbin
case. Change the bobbin.
Short circuit of fuse on the
cutting circuit.
Failed connection on
terminal or solenoid.
Solenoid failure.
Broken TR cutting driver.
When the upper thread is
too short, check the tension.
Check for damage on the
movable blade.
If the lower (bobbin) thread
is too short, check that the
thread is coming off the
bobbin easily. Use quality
bobbins to ensure the thread
is not too weak or does not
stretch too much.