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Mechanical Failures
False Thread Breaks
False thread breaks on the machine are usually caused when the upper tension is too loose, such that the
thread sensor fails to detect the thread moving against the thread sensor bar.
Step Symptom/Procedure
Condition
Solution/Step
1
Check upper thread tension
Too loose
Adjust thread feed parameters
in the software
Correct Tension
Go to Step 2
2
Tighten the thread feed pa-
rameters (reduce the amount
of thread feed in and see if
problem goes away)
Problem goes away
Tension was too loose
Problem still occurs
Go to Step 3
3
Inspect condition of thread
feeder rollers. They may be
damaged or worn.
Damaged or worn
Replace rollers
Rollers all good
Go to Step 4
4
Replace thread break sensor
assembly
Problem goes away
Sensor is bad
Problem still occurs
Contact Technical Support
Loose/Looping Stitches
Possible Causes
Solutions
Thread feed settings too low
Troubleshoot the thread feeder assembly. Check
the adjustment of the tread feed parameters in the
Bravo OS software. Contact Technical Support if
necessary.
Bobbin tension too low
Adjust the bobbin tension by tightening the screw
on the bobbin case. Refer to the Operator Manual
for instructions.
Uneven thread size
Replace with quality thread
Rotary hook timing is incorrect
Adjust hook timing
Inadequate rotary hook lubrication
Lubricate the rotary hook
Thread feeder roller worn or damaged
Replace thread feeder roller
Design density too tight
Decrease density (refer to Bravo OS manual for
design editing)
Needle Breaks
Possible Causes
Solution
Needle is bent
Replace needle
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