ELNA eXperience 620 Service Manual page 5

CONDITION
6. NOISY 1. BACKLASH BETWEEN HOOK
OPERATION GEAR AND LOWER
SHAFT GEAR IS TOO GREAT.
2. LOWER SHAFT GEAR IS
LOOSE.
3. INAPPROPRIATE BELT
TENSION.
4. NOT ENOUGH OIL.
1. INAPPROPRIATE FEED
7. DEFORMATION
BALANCE.
PATTERN
2. INAPPROPRIATE ZIGZAG
SYNCHRONIZATION.
3. UPPER THREAD TENSION
IS TOO STRONG.
CAUSE HOW TO FIX
SEE MECHANICAL ADJUSTMENT
"BACKLASH (LOWER SHAFT GEAR)".
ELIMINATE THE LOOSENESS.
SEE PART REMOVAL AND
REPLACEMENT "DRIVING MOTOR
(DC MOTOR)".
OIL ALL MOVING PARTS.
SEE MECHANICAL ADJUSTMENT
"STRETCH STITCH FEED BALANCE".
SEE MECHANICAL ADJUSTMENT
"ZIGZAG SYNCHRONIZATION".
SEE MECHANICAL ADJUSTMENT
"NEEDLE THREAD TENSION".
3
MODEL: eXperience 620
REFERENCE
P. 15
P. 27
P. 36
P. 19
P. 17
P. 18