Brother HE-800C - Uneven Seams; All Stitches

HE-800C
11. TROUBLESHOOTING
85
11-12. Uneven seams (10) …… All stitches
Items with a “*” in the “Page” column should only be handled by a qualified technician.
Cause Check Remedy Page
Threading Upper thread threading Thread the upper thread correctly. 22
Lower thread threading Thread the lower thread correctly. 25
Thread path Flaw or abrasion on the
thread path
Polish with buff or replace the part.
Especially, pay attention to finishing around needle
plate hole.
*
Needle Needle installation Insert needle fully into needle bar. 21
Needle size Replace needle with thicker one. *
Thread chips or dust Rotary hook rim
Rotary hook edge
Around needle plate hole
Remove thread chips or dust.
63, 64
Upper thread Upper thread tension Increase upper thread tension while checking stitches. 26, 27
Thread and needle Replace needle with one that fits for the thread. –
Rotary hook holder Flaw on the rotary hook
holder
Polish with buff or replace the part.
*
Rotary hook holder and
inner rotary hook overlap
amount
Adjust the rotary hook holder and inner rotary hook
overlap amount.
67*
Rotary hook Rotary hook lubrication Decrease the quantity of lubrication oil.
* Note that if you reduce the amount of oil too much,
thread breakages may occur.
16*
Bobbin winder tension
bracket
Bobbin thread tension Use the tension nut to adjust the lower thread winding
tension.
24
Uneven bobbin winding Move bobbin winder tension bracket up and down to
adjust.
24
Lower thread Lower thread tension Adjust the lower thread tension. 26
Bobbin case Damaged outside of bobbin
case and bent bobbin
holder spring, etc.
Polish with buff or replace the part.
* Use the HE-800C bobbin case.
*
Stitch patterns Purl stitch, whip stitch Set using parameter number 53. 40
3996Q
3997Q
Needle plate hole
Adjust the rotary hook
overlap amount.
Check flaw here