SunStar SPS/D-B1201 SERIES User Manual page 48

No Problems
6
Errors in thread tension
7
Errors in trimming
48
Causes
Weak tension of the upper thread
Weak tension of the lower thread
Incorrect timing of the needle and the shuttle
Loose crossing tension between the
movable and fixed blades
Abrasion of blade edges of the movable and fixed blades
Wrong position of the trimmer cam
Troubleshooting
Adjust the tension of the upper thread
Adjust the tension of the lower thread
Adjust the timing of the needle and the shuttle
Adjust the tension of the fixed blade
Replace the movable and fixed blades
Adjust the position of the trimmer cam