Checking The Machine Solenoids; Checking The Motor - Brother MD-602 Service Manual

13.3 Checking the machine solenoids

1. Remove the load connector (12P connector) of the machine from the connector part of the control box.
2. Measure with the tester set in the resistance range × 1 as follows.
Connector from the machine head
Reverse switch
0 Ω
pressed
∞ Ω
released
7.4 Ω
Reverse solenoid
5.0 Ω
Thread wiper
solenoid
8.0 Ω
Nipper
solenoid

13.4 Checking the motor

1. Remove the motor cord (4P connector) from the connector part of the power board.
2. Measure with the tester set in the resistance range × 1 as follows.
U
W
MOTOR
GND
6.7 Ω
Thread trimming
solenoid
(B737)
GND
6.7 Ω
Thread trimming
solenoid
(B883)
GREEN/YELLOW
RED
BLACK
WHITE
V
MD-602, 612
Presser foot lift connecter
Solenoid
9.5 Ω
Presser foot
lift switch
2.6 Ω
2.6 Ω
2.6 Ω
GND
0 Ω
pressed
∞ Ω
released
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