Brother BES-1240BC Instruction Manual page 259

Problem
Machine operation abnormal
Upper shaft locks at a certain point
in one cycle
"E-b1" error display
Upper shaft pulley does not turn.
Stitches cannot be made.
• Is any set screw of the rotary encoder loosened?
• Is any set screw of the machine pulley loosened?
• Is any set screw of the machine motor pulley loosened?
• Is the XY carriage belt loosened?
• Is the XY carriage belt damaged?
• Are any set screws for the XY pulley loosened?
• Are any set screws for the coupling of the XY pulse motor
loosened?
• Is embroidery data normal?
• Is the thread take-up stopped due to interference with the upper
case cover?
[Adjustment]
Thread take-up
Upper case cover
Needle case
Thread guide
Loosen the hexagon socket head cap screw of the thread take-
up operating lever and adjust the take-up movable range.
Tighten it securely afterwards.
• Are the needle bar clamp and the top dead center stopper
positioned correctly?
• Check the rotary hook of a machine head whose MENDING lamp
(green) is blinking to see if the thread is caught.
[Adjustment]
1.Take out the thread tangled in the rotary hook race so that
the rotary hook can be rotated forcibly by manual operation.
2.Check that the machine pulley is set to 100˚ of the scale, and
press the END switch.
[Measures]
1.If the thread end is left too long or stitching is left loosened
before starting embroidering, the thread is caught in the
machine and operation stops.
2.When starting embroidering, hook the thread end on the
spring or hold it with a hand.
3.Leave thread of about 60 ~ 70 mm from the needle hole when
starting embroidering.
• Is the presser foot lifted at a retract position when the power is
turned on?
Lower the presser foot for the four machine heads using the
lever.
• Is the needle attached properly?
• Is the timing of the needle and rotary hook correct?
BES-940BC • BES-1240BC
Chapter 12 Trouble Shooting
Check Point
Bolt
Thread take-up
operating lever
257