Troubleshooting - Brother BAS-311G Instruction Manual

12. TROUBLESHOOTING

• Please check the following points before calling for repairs or service.
• If the following remedies do not fix the problem, turn off the power switch and consult a qualified technician or the place of
purchase.
Turn off the power switch and disconnect the power cord before carrying out troubleshooting.
If the foot switch is depressed by mistake, the sewing machine might start operating and injury could result.
Problem
Work clamp does not
lift.
Work clamp does not
drop.
Work clamp lift amount
is incorrect.
Work clamp does not
lift to the maximum
height.
Thread wiper does
not operate correctly.
Lower thread winds
to one side.
Lower thread winding
amount is incorrect.
Thread slips out of
the needle.
Cause
Work clamp moves stiffly.
Air tube of presser lifter cylinder is bent
or damaged (Pneumatic specifications).
Work clamp moves stiffly.
Air tube of presser lifter cylinder is bent
or damaged (Pneumatic specifications).
Work clamp lift amount setting at
operation panel is incorrect (Solenoid
specifications).
Work clamp arm lever position is
incorrect. (Pneumatic specifications)
Work clamp arm stopper position is
incorrect (Solenoid specifications).
Cylinder joint position
(Pneumatic specifications)
The thread wiper is obstructing the
needle.
Thread wiper position is incorrect.
Bobbin winder tension assembly height
is incorrect.
Bobbin presser position is incorrect.
Stitches being skipped at the sewing
start.
Upper thread length is irregular.
Position of shuttle race thread guide is
incorrect
BAS-311G, BAS-326G
CAUTION
Apply a suitable amount of grease to the
sliding parts of the work clamp.
Straighten the bend in the tube or
replace the tube.
Apply a suitable amount of grease to the
sliding parts of the work clamp.
Straighten the bend in the tube or
replace the tube.
Change the work clamp lift amount
setting.
Adjust the position of the work clamp
arm lever.
Adjust the position of the stopper.
is incorrect.
Adjust the position of the cylinder joint.
Adjust the height of the thread wiper.
Adjust the stroke of the thread wiper.
Adjust the stroke of the thread wiper.
Adjust the height of the bobbin winder
tension assembly.
Adjust the position of the bobbin presser.
Refer to "Skipped stitches occur".
Adjust the sub-tension.
Adjust the position of the shuttle race
thread guide.
12. TROUBLESHOOTING
Remedy Reference
P. 29
P. 63
P. 60
P. 60
P. 60
P. 20
P. 20
P. 68
P. 22
P. 56
67