Storage; Servicing; Trouble Shooting - Pfaff coverlock 4.0 Owner's Manual

Storage

When the machine is not in use, be sure to keep it unplugged. Cover the machine with the dust cover to protect it from
the dust. Store the machine, so it is not exposed to direct sunlight or humidity.

Servicing

If you have any questions regarding service and/or operation, contact your local PFAFF® dealer.

Trouble shooting

Problem
Fabric does not feed well
Needle breaks
Thread breaks
Skipped stitches
Irregular stitches
Fabric puckers
Irregular trimming
Fabric jams
Machine does not operate
42 Maintenance
Solution
- Lengthen stitch length.
- Increase presser foot pressure for heavyweight fabric.
- Decrease presser foot pressure for lightweight fabric.
- Check the differential feed.
- Insert needle correctly.
- Do not pull fabric while sewing.
- Tighten needle set screw.
- Use a larger size needle on heavy fabrics.
- Check threading.
- Check for tangled or caught thread.
- Insert needle correctly.
- Insert new needle, current needle may be bent or have a blunt point.
- Use high quality thread.
- Loosen thread tension.
- Insert new needle, current needle may be bent or have a blunt point.
- Tighten needle set screw.
- Insert needle correctly.
- Change type or size of needle.
- Check threading.
- Increase presser foot pressure.
- Use a high quality thread.
- Balance thread tension.
- Check for tangled or caught thread.
- Check threading.
- Loosen thread tension.
- Check for tangled or caught thread.
- Use high quality lightweight thread.
- Shorten stitch length.
- Decrease presser foot pressure for lightweight fabrics.
- Check the differential feed.
- Check alignment of cutters.
- Replace one or both cutters.
- Check for tangled or caught thread.
- Compress thick layers of fabric with conventional machine before sewing with
overlock.
- Connect machine to power source correctly.