Singer 522D Instruction Manual And Parts List page 22

Problems
1. Wrong threading
2. Thread is thicker than needle hole
Loosen stitches
3. Inadequate thread tension
4. Needle thread is not lubricated
5. Wrong setting of needle and loopers
1. Wrong threading
2. Thread stand installed wrong
3. Lower knife installed wrong
4. Knives do not trim neatly
Uneven stitches
5. Thread disc or guide is burred
6. Needle point is damaged
7. Inadequate height of feed dog
8. Inadequate thread tension
1. Thread tension is too strong
2. Inadequate pressure of presser foot
3. Inadequate height of feed dog
Wrinkled stitches
4. Knives do not trim neatly
5. Differential feed is not matched
6. Needle is too thick
7. Seam width is too narrow against the chain-off finger
1. Presser foot installed wrong
2. Inadequate timing of looper thread cam
3. Double chain looper installed wrong
Thread chain
4. Wrong threading
does not come
out smoothly
5. Inadequate thread tension
6. Wrong relation between needle and looper
7. Needle plate, thread disc or presser foot ar burred
8. Thread tension disc is rough
For control system.
The motor has not operated properly.
E1 1. Sewing material is too heavy.
2. The machine needs lubrication.
The motor has over-current or under-voltage
E2
1. The motor power supply is not a proper voltage.
The motor has not function
E3
E4 The signal of the motor hall is wrong
Troubleshooting
Possible Causes
High Speed Flat Bed Interlock Sewing Machine
Possible Solutions
1. Rethread the machine correctly
2. Use proper needle for fabric and thread
3. Readjust the thread tension unit
4. Fill in the silicon oil
5. Readjust needle and loopers
1. Rethread the machine correctly
2. Install thread stand correctly
3. Install lower knife correctly
4. Readjust knife and/or sharpen or replace it
5. Grind off, polish or replace by a new part
6. Change the needle
7. Readjust the feed dogs
8. Readjust the thread tension unit
1. Readjust the thread tension unit
2. Readjust presser foot pressure
3. Readjust the feed dogs
4. Readjust knife and/or sharpen or replace it
5. Readjust differential feed ratio
6. Use proper needle for fabric and thread
7. Readjust seam width or replace chain-off finger
1. Reinstall presser foot correctly
2. Readjust looper thread cam
3. Reinstall double chain looper correctly
4. Rethread the machine correctly
5. Readjust the thread tension unit
6. Readjust needle and looper
7. Grind off, polish or replace by a new part
8. Polish thread tension disc
1. Change to a lightweight material.
2. Applying lubrication oil.
1. Check the voltage of the motor
1. Main switch 'Off' and 'On' again
2. Replace new ES DD motor
1. Check the motor connector and wire condition.
2. Replug the motor connector.
3. Replace new ES DD motor.
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