Thread Cutter Does Not Work Normally - Brother NV4000D Service Manual

Failure Investigation for Electronic Parts Thread cutter does not work normally
Do the thread hook assy. and lever
gear move easily?
Is the resistance between pins 1 &
1, 2 & 2, 3 & 4, and 4 & 3 at the
ends of the C pulse motor lead wire
1Ω or less?
Is the resistance between the 1 & 2
pins and 3 & 4 pins on the C pulse
motor connectors (CN11) 5 - 7Ω?
Thread cutter does not operate
normally
Y
Y
Y
Replace main PCB assy.
N
Adjust the assembly of the
thread cutter module
N
Replace the C pulse motor
lead wire.
N
Replace C pulse motor
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