Main Motor Rotation Is Not Normal - Brother CE-5500PRW Service Manual

Failure Investigation
for Electronic Parts
The rotation of the main motor is unstable.
The rotation speed does not reach maximum.
The rotation speed can not be adjusted.
Is the main motor connector
connected to the power supply
PCB assy. (CN401) correctly?
Is the power lead wire assy.
connector connected to the power
supply PCB assy. (CN201) and the
main PCB assy. (CN5) correctly?
When the speed control lever is
moved with the power ON, does
the voltage between pin 4 and 5 of
CN1 on the SSVR PCB assy. 0.7-
4.2V DC?
5 - 12

Main motor rotation is not normal

or
or
Y
Y
Is the main PCB assy. attached
correctly?
(Is the BW switch OFF?)
Y
Replace the main PCB assy.
N
Connect it correctly.
N
Replace the SSVR PCB assy.
N
Attach the main PCB assy.
correctly.