Cannot Sew Button Holes Well - Brother NV4000D Service Manual

Failure Investigation for Electronic Parts Cannot sew button holes well
5 - 12

Cannot sew button holes well

Is the correct presser being used?
Y
Is the resistance between pins 4 and 5 on
the BH switch connector (CN21) normal?
BH lever down : 1Ω or less
BH lever up : ∞
Y
When the BH lever is lowered, is
the resistance between pins 1 & 2
and 2 & 3 on the BH switch
connector (CN21) normal?
BH lever pulled forward
Pins 1 - 2 : 1 Ω or less, pins 2 - 3 : ∞
BH lever pushed back
Pins 1 - 2 : ∞, pins 2 - 3 : 1 Ω or less
Y
Replace main PCB assy.
N
Change to correct presser
Adjust BH lever
N
or
Replace BH switch assy.
Adjust BH lever
N
or
Replace BH switch assy.