HE-800B
11. TROUBLESHOOTING
155
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.
INSTRUCTION
MANUAL CD
Lower thread threading
Thread the lower thread correctly.
INSTRUCTION
MANUAL CD
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.
INSTRUCTION
MANUAL CD
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.
–
Upper thread
Upper thread tension
Increase upper thread tension while checking stitches.
INSTRUCTION
MANUAL CD
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.
91
Rotary hook holder and
inner rotary hook overlap
amount
Adjust the rotary hook holder and inner rotary hook
overlap amount.
91
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.
109
Bobbin winder tension
bracket
Bobbin thread tension
Use the tension nut to adjust the lower thread winding
tension.
–
Uneven bobbin winding
Move bobbin winder tension bracket up and down to
adjust.
INSTRUCTION
MANUAL CD
Lower thread
Lower thread tension
Adjust the lower thread tension.
INSTRUCTION
MANUAL CD
Bobbin case
Damaged outside of
bobbin case and bent
bobbin holder spring, etc.
Polish with buff or replace the part.
*
Use the HE-800B bobbin case.
–
Stitch patterns
Purl stitch, whip stitch
Set using parameter number 53.
INSTRUCTION
MANUAL CD
3996Q
3997Q
Needle plate hole
Adjust the rotary hook
overlap amount.
Check flaw here
Summary of Contents for HE-800B
Page 7: ...v HE 800B Oil tank accessory 4732M 4731M 4730M ...
Page 75: ...6 ASSEMBLY HE 800B 66 D E 0688D 0690D ...
Page 126: ...9 ELECTRIC MECHANISM HE 800B 117 Power PCB Cutter PCB LCD panel PCB 0831D 0768D 0769D ...
Page 133: ...9 ELECTRIC MECHANISM HE 800B 124 0851D ...
Page 134: ...9 ELECTRIC MECHANISM HE 800B 125 0852D ...
Page 135: ...9 ELECTRIC MECHANISM HE 800B 126 0853D ...
Page 177: ...MEMO 168 HE 800B ...
Page 178: ...SERVICE MANUAL 2014 Brother Industries Ltd All Rights Reserved HE 800B I3061003D 2014 03 D 1 ...