22. TROUBLESHOOTING
SL-710A
136
22. TROUBLESHOOTING
• Please check the following points before calling for repairs or service.
• If the following suggestions do not solve the problem, turn off the machine power supply and contact your nearest
Brother service center.
DANGER
Wait at least 10 minutes after turning off the power switch and disconnecting the power cord from the wall
outlet before opening the face plate of the control box. Touching areas where high voltages are present can
result in severe injury.
CAUTION
Turn off the power switch and disconnect the power cord before carrying out troubleshooting, otherwise the
machine will operate if the treadle is pressed by mistake, which could result in injury.
22-1. Sewing
Problem
Possible cause
Page
1. Upper thread is not
tight.
• Is the upper thread tension too weak, or is the lower thread tension too
strong?
Adjust the upper thread tension or lower thread tension.
• Is the needle and feed mechanism timing correct?
Advance the needle timing.
Instruction manual
67
2. Lower thread is not
tight.
• Is the lower thread tension too weak, or is the upper thread tension too
strong?
Adjust the lower thread tension or upper thread tension.
Instruction manual
3. Loops appear in seam.
• Is the thread path not smooth enough?
Use a file with a fine grain or sandpaper to polish smooth the thread
path.
• Is the bobbin not turning smoothly?
Pull out the lower thread to check that there is no slackness in the thread
tension, or replace the bobbin or bobbin case.
-
Instruction manual
4. Skipped stitches occur
while sewing.
• Is the needle tip bent? Is the needle tip blunt?
If the needle tip is bent or broken, replace the needle.
• Is the needle properly installed?
If it is incorrect, install the needle correctly.
• Is the machine properly threaded?
If it is incorrect, thread the thread correctly.
• Is the presser foot pressure too weak?
Adjust the presser foot pressure.
• Is the needle too thin?
Replace the needle with a needle that is one rank thicker.
• Is the presser foot too high?
Adjust the height of the presser foot.
• Is the needle and rotary hook timing incorrect?
Adjust the height of the needle bar.
Adjust the clearance between the needle and the rotary hook.
• Is the thread tension spring too weak?
Adjust the tension of the thread tension spring.
• Is the rotary hook tip broken?
If it is broken, replace the rotary hook.
-
Instruction manual
Instruction manual
Instruction manual
-
64
67
68
63
48
0573M
0574M
0977M
0470M
To Next Page
Loading...
