Brother PR655 - Thread Breakage Detection Does Not Function Normally

Failure Investigation
for Electronic Parts
Failure Investigation for Electronic Parts
Failure Investigation
for Electronic Parts
5 - 9
Thread breakage detection does not function normally.
Thread breakage detection does
not function normally.
Connect it properly.
N
Y
Y
Is the FFC for the thread quantity sensors
properly connected to each thread quantity
sensor and connectors (CN1 - CN6) on the head
PCB? Is the orientation of the FFC correct?
Connect it properly.
N
Y
Is the head lead properly connected to
connector CN7 on the head PCB and
connector CN9 on the main PCB?
Change the TH (thread
quantity) sensor's FFC.
N
Y
Is the resistance between each terminal at both
ends 1 or below when the TH (thread quantity)
sensor's FFC is removed from the PCB?
Change the lead wire assy:head.
N
Y
Is the resistance between each pin at both ends
1 or below when connectors at both ends of
the head leads are removed from the PCB?
Does the machine function normally
when the TH (thread quantity) sensor
PCB is replaced with a reliable one?
Does the machine function
normally when the head PCB is
replaced with a reliable one?
Change the TH (thread
quantity) sensor PCB.
Y
N
Change the main PCB.
N
Change the head PCB.