Brother S-710A Service Manual page 147

Problem
18.Machine does not
operate when power is
turned on and treadle
is pressed.
1) Operating panel power
indicator does not
illuminate.
2) Only operating panel
power indicator
illuminates.
1001M
3) Operation panel operates
normally.
19. Machine does not
operate at high speed.
20. Thread is trimmed
when treadle is
returned to the
neutral position.
21. Startup is slow.
• Is the power supply connector
disconnected from the control
box?
Insert the connector securely.
• Is the power supply plug incorrectly wired or is the voltage incorrect?
Check the power plug wiring and the power supply voltage. (Try
inserting into a different wall socket.)
• Is DIP switch No.8 inside the
control box set to ON?
Set DIP switch No.8 to OFF.
• Is the treadle unit connector
inside the control
disconnected?
Securely connect the connector.
• Has the treadle unit or control circuit board been replaced?
Adjust the depression stroke to the standard setting.
• Is operation possible using the standing operation pedal?
If operation is not possible, turn the power off and then back on again.
• Is the sewing speed setting or backtack speed setting incorrect?
Set the speed to a higher speed using the operating panel.
• Is the FVR inside the control box
at the maximum setting?
Turn the FVR clockwise to the
maximum setting.
• Treadle unit signal abnormality.
Adjust the depression stroke to the standard setting.
• Treadle unit signal abnormality.
Adjust the depression stroke to the standard setting.
• Is the FVR inside the control box
at the maximum setting?
Turn the FVR clockwise to the
maximum setting.
Possible cause
box
SL-710A
22. TROUBLESHOOTING
Page
Instruction manual
1002M
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1003M
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0998M
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Instruction manual
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1920M
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92
80
1920M
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