The Motor Starts, Then Stops Immediately; Speed Cannot Be Adjusted; Needle Does Not Stop In The Up Position; Low Speed - Brother STAR240E Service Manual

The motor 1. Is the sensor PC board assembly installation normal?
4.
starts, then
stops 2. Others
immediately.
5. Speed cannot 1. Is the transistor output normal? Is the voltage
be adjusted.
2. Is the voltage between 5V and ground on the motor
3. When the power is switched ON and the speed
4. Others
6. Needle does 1. Is the NP sensor shutter position normal?
not stop in the
up position. 2. Are the sensor PC board assembly and main PC
3. Is the bobbin winder switch normal?
4. Does the voltage between (+) 4 and (-) 3 on
5. Others
7. The sewing 1. Does the reverse sewing button operate correctly?
machine does
not turn when 2. Is the reverse sewing button normal?
the reverse
sewing switch
is pressed or if
the switch is 3. Others
pressed during
operation, it
does not go into

low speed.

(However,
when the foot
controller is
used, the speed
is not supposed
to become slow
speed.)
Is it floating loose or tilted?
between Pins 9-10 of the transistor approximately 9
volts?
control PC board normal?
5±0.25 VDC
adjustment control is slid, does the voltage between
(+) 2 and (-) 1 of the connector on the SS-VR PC
board vary between 0 and 5 VDC?
board assembly installation normal? Are they
floating loose or tilted?
Resistance between 1-2 on connector CN3 (red)
On..........1Ω max.
Off..........Infinite
connector CN5 change between 0 and 5 V when the
sewing machine is turned by hand?
Resistance between 1-2 on connector CN2 (yellow)
On..........1Ω max.
Off..........Infinite
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1. Correct the installation.
2. Replace the main PC board
assembly.
1. Replace the main PC board
assembly.
2. Replace the main PC board
assembly.
3. Replace the SS-VR board
assembly.
4. Replace the main PC board
assembly.
1. Check and adjust as
necessary.
2. Correct the installation.
3. Replace the bobbin winder
switch assembly.
4. Replace the main PC board
assembly.
5. Replace the main PC board
assembly.
1. Check the mechanism and
adjust as necessary.
2. Replace reverse sewing
switch assembly.
3. Replace the main PC board
assembly.