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HE-800C
11. TROUBLESHOOTING
81
11-3. Uneven seams (1) …… At the sewing start
Items with a “*” in the “Page” column should only be handled by a qualified technician.
Cause Check
Remedy
Page
Upper thread trimmer
Installation height
Adjust the upper thread trimmer installation height.
69*
Upper thread trimmer
opening timing
Adjust to an appropriate opening timing.
70*
Upper thread trimmer
operation
Apply grease to the inclined face of the opening cam.
70*
Upper thread feeding
Thread take-up amount
Loosen the screw to decrease thread take-up amount
so that upper thread does not pull out of trimmer
assembly at the sewing start.
*
Lower thread (bobbin
slip)
Lower thread tension
Adjust the lower thread tension appropriately.
26
Bobbin holder spring
Add tension to the bobbin holder spring.
.
*
Lower thread retainer
position
Adjust the lower thread retainer position.
* Adjust lower thread retainer so that a 35 - 40 mm
thread leader is left after trimming.
*
Bobbin presser position
Adjust the bobbin presser position.
71*
Bobbin insertion
Insert the bobbin correctly.
25
4000Q
Screw
Increase
Decrease
4001Q
Add tension to the spring by the same
amount that the bobbin tab is projecting.
Make a gap
4002Q
35 - 40mm