Brother HS-3000, Service Manual

Page: 149 / 164

6 - 6
Repair Manual
10 Threading not
possible
Thread pushed out at the hook
end Threading
function Check that when
threading is carried out
with Schappe Spun
Sewing Thread #60 /
#11 needle and
Schappe Spun Sewing
Thread #30 / #16
needle, that the
threading lever moves
smoothly and that
threading through the
needle hole is possible.
• Vertical slippage in needle
thread block
Adjust needle thread (4-12)
Hook extends right of the needle
hole
• Wide gap between right side
of needle and hook guide
Replace threader hook assy.
(2-31) (3-48)
• Needle curvature Replace needle
• Needle slant (hole slant with
slanted attachment of
needle block)
Replace needle bar
(2-33) (3-46)
• Threader hook assy.
slippage
Replace threader hook assy.
(2-31) (3-48)
When the threader
lever returns, it
stops part way
through. Threader shaft tangling Replace needle holder assy.
(2-34) (3-44)
Bad thread guide shape Replace threader hook assy.
(2-31) (3-48)
Needle thread shaft and top gap
too small Replace needle holder assy.
(2-34) (3-44)
Needle thread
lever operation
catches part way
through. Bad needle stop position
• NP sensor damage Replace main PCB assy.
(2-13) (3-13)
• Grease or dirt adhering to
NP sensor
Remove grease and dirt
• Rotation shutter damage Replace upper shaft assy.
(2-17) (3-8)
• Bad needle thread block
rotational position
Adjust needle thread block
(4-12)
11 Either upper thread
tension or lower
thread tension
Upper thread tension is tight/
loose Adjust upper thread tention
(4-5)
Upper thread
tension Check that the thread
tension is good during
actual sewing.
Lower thread tension is too tight/
loose Adjust lower thread tension
(4-21)
Lower thread
tension
Upper thread or lower thread
unsuitable Replace upper thread or lower
thread
Problem Primary factors and causes Repair method Items for
Inspection
Inspection method
and standards