Brother PR655 Service Manual page 268

Failure Investigation for Electronic Parts
Does the machine function normally
when the power supply PCB unit is
replaced with a reliable one?
The main shaft does not rotate normally.
From the previous page
Y
Y
Y
N
Change the main PCB.
5 - 13
N
Change the main motor.
N
Change the lead wire assy:
power motor.
N
Change the lead wire assy:
power signal.
Y
Change the power supply
PCB unit.