SunStar HC Series User Manual page 64

Error Type
Puckering Excessive thread tension
Excessive pressure of
presser foot
Needle failure
worn out/damaged needle
tip
needle is too large for thread
Needle hole is too large for
needle
Short-circuit of trimming
Trimming failure
fuse
Poor connection/quality of
trimming solenoid
Bad connection
Trimming driver TR
damaged
Cause
Adjust tension
Change presser foot spring
Change needle
Use adequate size of needle
Check and change fuse F1 in
joint board
Check and change solenoid and
solenoid connection
Check connection
Change joint board
Inspection & Repair Reference
SWF/ needle holes
are 2.0mm
Check fuse spec