Brother DB2-DD7100, Service Manual

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22. TROUBLESHOOTING
SL-710A
142
Problem Possible cause Page
27.
The thread trimmer and
thread wiper solenoids
do not operate.
•
Is memory switch No. 11 set to ON?
Set memory switch No. 11 to OFF.
•
Are the solenoid resistances normal?
If the resistances are not normal, replace the solenoids.
•
Is the 8 A fuse inside the control box
blown?
If the 8 A fuse is blown, check
the resistances of all the
solenoids, and replace any
solenoid that has an abnormal
resistance.
After this, replace the 8 A fuse.
87
104
104
28.
Motor does not operate
smoothly, or motor
makes an abnormal
noise.
•
Problem with speed sensor.
Replace the motor.
34
29. Fluorescent lamp
flickers.
•
This can occur if the power supply capacity is not sufficient.
Adjust the FVR inside the control box.
The flicker is reduced when the FVR is turned to the left.
(The sewing machine start-up also becomes slower when this is done.)
80
30. The illumination lamp
does not turn on.
•
Is the lamp blown?
Replace the lamp (6 V).
•
Is the 5 A fuse inside the control
box blown?
Replace the 5 A fuse.
•
Is the lamp cord disconnected
from the terminal board inside
the control box?
Securely connect the cord.
•
Is the CN9 connector inside the
control box disconnected?
Securely connect the connector.
-
80
80
80
31. Stitch number display
on operation panel is
flashing.
•
Problem with control box.
Replace the control box.
76
32. Some other operating
problem is found.
•
Clear the memory data. The settings will be returned to their factory
defaults.
•
Adjust the depression stroke to the standard setting.
102
92
1924M
1919M
CN9
5 A fuse
Terminal
board