Brother HE-800A Service Manual

HE-800A
5. TROUBLESHOOTING
107
Cause Check Remedy Page
Lower thread tension Adjust the lower thread tension appropriately.
Instruction
manual
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.
96
Bobbin presser position Adjust the bobbin presser position. 98
Bobbin insertion Insert the bobbin correctly.
Instruction
manual
Lower thread (bobbin
slip)
Work clamp lifting speed Reduce the setting for memory switch No. 02.
Instruction
manual
5-4. Uneven seams (2) …… Lower thread is lifted up at the sewing start
The end of the lower thread protrudes above the seam at the sewing start
Cause Check Remedy Page
Lower thread retainer Lower thread retaining
amount
Adjust the lower thread retaining amount.
96
Lower thread clamp
opening timing
Adjust so that the lower thread clamp plate opens
when the feed mechanism moves 6 – 7 mm.
97
Lower thread clamp
Lower thread clamping
force
⋅ If the lower thread clamp and lower thread presser
are bent, replace them.
⋅ Check that the screws are tightened.
-
4003Q
3999Q
Lower thread
clamp
Screw
4001Q
Add tension to the spring by the same
amount that the bobbin tab is projecting
Make a gap
4002Q
35 - 40mm

Brother HE-800A Specifications

General

Brand	Brother
Model	HE-800A
Category	Sewing Machine
Language	English