Brother PR655 - A Needle Is Not Threaded Normally

Failure Investigation for Electronic Parts
Failure Investigation
for Electronic Parts
Failure Investigation
for Electronic Parts
5 - 16
A needle is not threaded normally.
A needle is not threaded normally.
Connect it properly.
N
Y
Y
Is the needle TH sensor's lead
properly connected to CN17 on the
main PCB?
Connect it properly.
N
Y
Is the TH motor's lead properly
connected to CN8 on the main
PCB?
Change the needle TH
sensor PCB.
Y
Does the machine function normally
when the needle TH sensor PCB is
replaced with a reliable one?
N
Change the TH motor.
N
Is the resistance between pins 1 and 2,
and 3 and 4 of the TH motor 4.7 - 5.7Ω,
respectively, when the motor's connector
CN8 is removed from the main PCB?
Change the main PCB.