Checking The Motor And Power Supply - Brother S-710A Service Manual

19. CHECKING THE MOTOR AND POWER SUPPLY

19. CHECKING THE MOTOR AND POWER SUPPLY
Turn off the power and disconnect the power plug from the wall outlet before carrying out these operations,
otherwise the sewing machine may operate if the treadle is pressed by mistake, and injury may result.
If the power switch needs to be left on when carrying out some adjustment, be extremely careful to observe all
safety precautions.
Motor
Power switch
<100 V type>
Ground wire
<200 V type>
103
CAUTION
Motor connector <4P>
Power supply connector <6P>
1827M
1883M
1884M
1. Disconnect the motor connector (4P) from the control box.
2. Measure the resistance of the motor connector using
an ohmmeter in the x1 range.
If the value is as shown in the table below, the
connector is normal.
Between 2 - 3
Approx. 2 - 3 Ω
Between 3 - 4
Between 4 - 2
1. Disconnect the power supply connector (6P) from the
control box.
2. Turn on the power switch.
3. Measure the voltage at the power supply connector
using the AC voltage range of a multimeter, and check
that the voltage is within the allowable range for the
specified voltage rating.
<100 V type (100 - 120 V)>
Measure the AC voltage between terminals 2 - 3.
<200 V type (200 - 240 V)>
[A] For three-phase
Measure the AC voltage between terminals 4 -
5, 5 - 6 and 6 - 4.
[B] For single-phase
Measure the AC voltage between terminals 4 -
6.
SL-710A