Brother NV-10A Service Manual page 191

Repair Manual
Problem Primary factors and causes
10 Sewing sounds
Inappropriate
sounds
• Thread take- Thread take-up lever shaft noise
up noise • Loose screws
• Outer rotary Outer rotary hook noise
hook vertical • Outer rotary hook vertical
rattle noise rattle
• Upper shaft Upper shaft bushing out of oil
noise
Rattle along the thread take-up
counter weight shaft
• Motor noise Belt too tight
Motor brush noise
• Lower shaft Lower shaft axial rattle
noise
• Vertical feed Vertical feed cam out of grease
cam noise
• Horizontal Bad horizontal feed arm
feed arm
noise
• Noise from Back/front and left/right rattle in
contact feed dog
between
Bad feed dog front-back position
needle plate A
adjustment
and feed dog
Bad feed dog left-right
adjustment
Needle plate A attachment
position slippage
• Needle Noise of contact between needle
contact noise and outer rotary hook
• Bad needle interference
adjustment
• Loose needle interference
adjustment screw
Repair method
Retighten thread take-up lever
shaft (2-36) (3-52)
Reattach outer rotary hook
(2-46) (3-65)
Lubricate sliding surfaces of
bushing and thread take-up
counter weight
Reattach thread take-up counter
weight (2-30) (3-9)
Adjust motor belt (4-6)
Replace main motor assy.
(2-18) (3-23)
Reassemble lower shaft assy.
(2-52) (3-57)
Lubricate lower shaft assy.
(3-58)
Replace feed arm A
(2-52) (3-56)
Reattach feed dog
(2-45) (3-65)
Adjust feed dog front and back
position (4-21)
Adjust feed dog left and right
position (4-21)
Reattach needle plate A
(2-45) (3-66)
Adjust needle interference
(4-10)
Adjust needle interference
(4-10)
Items for Inspection method
Inspection and standards
Operating noise Check that there is no
abnormal noise at fast,
middle and slow speed
in 3 point drop (test
mode 3).
6 - 5