Brother S-7300A Instruction Manual page 106

14. TROUBLESHOOTING
Problem
22 Incorrect thread trimming
(Upper thread is not being
trimmed.)
(Lower thread is not being
trimmed.)
0.1 - 0.3mm
23 Broken needle
24 Oil gauge (1) is not visible
in oil gauge window.
25 The presser foot does not
lift using the knee lifter.
26 Thread take-up
stopper and
take-up spring are twisted
together.
95
・ Is the needle properly installed?
If it is incorrect, install the needle correctly.
・ Is the fixed knife or movable knife blunt?
Replace the fixed knife or the movable knife.
・ Tilt the upper knife forward slightly. (About 0.1 to 0.3 mm)
・ Is there not enough of a meshing amount between the upper knife
and the lower knife?
Check that the tip of the upper knife comes to the lower knife
index position so that the knives mesh.
0949D
・ Is the material being pushed or pulled with excessive force during
sewing?
・ Is the needle properly installed?
If it is incorrect, install the needle correctly.
・ Is the needle tip bent? Is the needle tip broken, or is the needle hole
blocked?
Replace the needle.
・ Is the needle and rotary hook timing correct?
Adjust the height of the needle bar.
Adjust the clearance between the needle and the tip of the
rotary hook.
・ Is the needle and feed mechanism timing correct?
Adjust to the standard timing.
・ Try pressing the special locus key and selecting No. 2 or No. 3.
0469M
NOTE:
・ It is extremely dangerous to leave any pieces of broken
needle sticking in the material.
If the needle breaks, search for all pieces until the whole of
the needle is found again.
・ Furthermore, we recommend that thorough steps be taken
to account for such needles to comply with product liability
regulations.
・
Is the oil tank empty?
Fill the oil tank with oil.
0923D
・
Is the knee lifter being used at the needle up position while thread
trimming is disabled?
Enable thread trimming.
・
Is the knee lifter being used before the sewing machine has stopped?
Adjust the tension release switching plate upward to retard the
tension release timing.
spring ・
Adjust the tension release switching plate upward to retard the
thread
tension release timing.
Possible cause
S-7300A
Page
16
82*
16
80*
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79*
65
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