Janome MC7700 QCP Service Manual page 41

STEP 6 (PHASE CHECK)
STEP 7 (DC MOTOR)
1) TURN THE HANDWHEEL TOWARD
YOU. THE "Phase state" CHANGES
"BM", "–", "FM" AND "–" IN ORDER.
"--" to "BM"
WHEN THE PHASE STATE IS AT
"BM", AND CONFIRM BUTTON IS
PRESSED, ZIGZAG WIDTH MOTOR
AND CUTTING MOTOR WILL BE
INITIALIZED.
WHEN THE PHASE STATE IS AT
"FM", AND CONFIRM BUTTON IS
PRESSED, FEED MOTOR WILL BE
INITIALIZED.
PRESS THE REVERSE STITCH
BUTTON TO PROCEED TO THE
NEXT STEP.
[CORRECT CONDITION]
LCD DISPLAYS "DCM".
PRESS START/STOP BUTTON OR
DEPRESS FOOT CONTROL.
THE MACHINE WILL RUN AT THE
SPEED SET BY THE SPEED
CONTROL LEVER.
PUSH THE BOBBIN WINDER
SPINDLE TO THE RIGHT.
PRESS START/STOP BUTTON OR
DEPRESS FOOT CONTROL.
THE BOBBIN WINDER SPINDLE
WILL RUN AT THE SPEED SET BY
THE SPEED CONTROL LEVER.
PRESS THE REVERSE STITCH
BUTTON TO RETURN TO THE
FIRST STEP.
39
[FAULTY CONDITION]
MOTORS WILL NOT BE
INITIALIZED WHEN CONFIRM
BUTTON IS PRESSED AT BM OR
FM PHASES.
THE DISPLAY SHOWS ERROR.
–REMEDY–
CHECK THE MOTORS IF THEY
ROTATE SMOOTHLY.
REPLACE THE MOTOR.
REPLACE THE CIRCUIT BOARD A.
[FAULTY CONDITION]
MACHINE SPEED DOES NOT
CHANGE.
–REMEDY–
CHECK THE MOTOR BELT
TENSION. REPLACE THE DC
MOTOR. REPLACE THE PRINTED
CIRCUIT BOARD A.