Brother S-710A - Page 148

22. TROUBLESHOOTING
SL-710A
141
Problem Possible cause Page
22. Sewing machine starts
operating before
presser foot is lowered
(solenoid-type presser
lifter specifications).
• Is DIP switch 2 inside the control
box set to OFF?
Set DIP switch 2 to ON.
81
23. Presser foot does
not lower (solenoid-
type presser lifter
specifications).
• Is the solenoid-type presser lifter
1P connector also connected?
If not using the 1P connector,
disconnect it.
• Treadle unit signal abnormality.
Adjust the depression stroke to the standard setting.
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92
24. Machine stops during
sewing.
• Is the power supply voltage too low?
Check the power supply.
(If the power cord is too long or too many appliances are being run from
a single outlet, this may cause voltage drops which will in turn cause the
reset function to activate and stop the machine, even if the power supply
itself is normal.)
103
25. Lower thread detector
does not operate.
• Is the lower thread detector
connector inside the control box
disconnected?
Insert the connector securely.
• Is the lower thread detector relay
cord inside the machine head
disconnected?
Securely connect the cord.
• Is memory switch No. 16 set to ON?
Set memory switch No. 16 to OFF.
Instruction manual
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87
26. None of the solenoids
operate.
• 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.
104
1921M
1922M
1923M
0993M
0994M