Chapter 11 Troubleshooting - Brother 940D Manual De Instrucciones

Troubleshooting
This sewing machine is designed for trouble-free operation. However, the following chart indicates trouble which
may occur if basic adjustments are not made properly.
Trouble
1. Does not feed
2. Needles break
3. Threads break
4. Skipped stitches
5. Stitches are not uni-
form
6. Fabric is puckered
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Cause
Presser foot pressure too loose
1. Needles bent, or needle tip blunt
2. Needles incorrectly installed
3. Material pulled forcibly
1. Improper threading
2. Thread tangled
3. Thread tension too tight
4. Needles incorrectly installed
5. Wrong needle used
1. Needle bent, or needle tip blunt
2. Needle incorrectly installed
3. Wrong needle used
4. Improper threading
5. Presser foot pressure too loose
Thread tensions are not adjusted
properly
1. Thread tension too tight
2. Improper threading or thread
tangled
Remedy
Turn the pressure adjustment screw clock-
wise to increase the presser foot pressure.
Replace with new needle.
Install needles correctly.
(See page 5.)
Do not press or pull material too hard when
sewing.
Thread correctly.
(See pages 18~28.)
Check spool pin, thread holders, etc. and
remove tangled thread.
See pages 31~36, "Thread tension".
Install needles correctly.
(See page 5.)
Use correct needle
Schmetz 130/705H – suggested
Replace with new needle.
Install needle correctly.
(See page 5.)
Use correct needle.
Schmetz 130/705H – suggested
Thread correctly.
(See pages 18~28.)
Turn the pressure adjustment screw clock-
wise to increase the presser foot pressure.
See pages 31~36, "Thread tension".
Decrease thread tension when sewing light-
weight or fine material.
(See pages 31~36.)
Thread correctly.
(See pages 18~28.)