Pfaff coverlock 4852 Owner's Manual page 65

Sewing problems and their solutions
This machine has been developed with ease of operation in mind. No diffi cult or tricky set tings
need to be made. Sewing problems of the kind described below may occur as a result of minor
adjustment and operating errors. They can be easily adjusted by following the in structions.
Problem
Needle breakage
Thread breaks
Skipping stitches
Stitch formation
faulty
3- or 4-thread
overedge seam has
an irregular
appearance and the
upper looper thread
has not interlocked
in the seam.
Machine will not
operate although
master switch is on.
Fabric not neatly
trimmed
Puckered seams
Fabric not fed
through evenly
Cause
The needle was bent or the
point damaged.
The needle was not fully
inserted.
The fabric was pulled too
fi rmly.
Incorrectly threaded.
Thread has caught.
Thread tension is too tight.
Needle not fully insert.
Incorrect needle used.
Needle bent or point
damage.
Needle not fully inserted.
Incorrect needle used.
incorrectly threaded.
Incorrect setting of thread
tension.
The converter is attached.
Power supply interrupted.
Waste thread between
upper and lower blade
Upper blade is blunt.
Thread tension too tight.
Incorrect setting of
differential feed.
Thread has caught due to
incorrect threading
Stitches too short.
Sewing foot pressure too
low for heavy fabrics.
Sewing foot pressure too
high for lightweight fabrics.
Solution
Insert new needle
(see page 13).
Insert needle fully
(see page 13).
Do not pull on the fabric when
sewing.
Thread properly (see page 14 - 23).
Check if the thread is caught on the
spool stand etc.
Correct the tension (see page 46 - 56).
Insert needle correctly (see page 13).
Use needle system EL X 705.
Insert new needle (see page 13).
Insert needle correctly (see page 13).
Use needle system EL X 705.
Thread properly (see page 14 23).
Re-set thread tensions (see page 46
- 56).
The converter must be removed (see
page 32).
Close looper cover (see page 8).
Clean blades.
Replace upper blade (see page 59).
Reduce thread tension.
Re adjust differential feed (see pages
36, 37).
Thread correctly (see pages 14 - 23).
Increase stitch length (see page 38).
Increase sewing foot pressure (see
page 28).
Reduce sewing foot pressure (see
page 28).
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