Brother TZ1 B651 Basic Repairs & Adjustments page 22

BOBBIN AND BOBBIN CASE
FAULTS
Bobbin case falls out
Bobbin case doesn't fit in bobbin base
Bobbins don't fit in bobbin case
BOBBIN WINDER FAULTS
Bobbin winder doesn't drive (bench tyoe)
Bobbin winder doesn't drive(internal type)
Bobbin winds unevenly
Bobbin thread too loose
Bobbin thread too tight
Bobbin doesn't fit on winder
Wnder winds too much onto bobbin
Winder winds too little on bobbin
CHECK SPRING FAULTS
Check spring breaks easily
Check spring jams
Check spring come to rest correctly
TROUBLE SHOOTING FOR
LOCKSTITCH SEWING MACHINES
Possible Fault
Bobbin case latch spring broken or weak
Bobbin too large
Bobbin case incorrectly fitted to bobbin base
Bobbin case incorrect type
Bent needle
Bobbin bent or buckled
Thread or swarf caught in bobbin case or base
Bobbin case incorrect type
Bobbin incorrect type or size
Bobbin bent or buckled
Thread or swarf caught in bobbin case
Incorrect bobbin
Possible Fault
Drive belt misaligned or not set close to drive
wheel
Drive belt too loose
Winder wheel seized
Thread is too tight or caught up in tension unit
or from thread stand
Drive wheel rubber is worn
Drive wheel rubber not close enough to drive
wheel shaft
Winder wheel seized
Thread is too tight or caught up in tension unit
or from thread stand
Tension too loose
Misaligned tension unit or guide
Tension too loose
Thread not in tension discs or guides
Tension too tight
Thread caught in guides or elsewhere
Incorrect bobbin
Centre of winder set to wide
Stop setting sset too late
Stop setting set too early
Possible Fault
Incorrect type of check spring
Check spring mechanism misaligned
Tension unit or check spring timing incorrectly
set
Possible Remedy
Replace the spring or fit a new bobbin case
Fit correct size bobbin
Remove case and refit
Replace bobbin case
Fit new needle
Fit new bobbin
Remove thread or swarf and refit
Fit correct bobbin case
Replace with correct bobbin
Replace bobbin
Remove swarf or thread
Replace bobbin with correct type and size
Possible Remedy
Realign winder to belt
Tighten drive belt
Oil centre of drive spindle
Rethread and set tension unit
Replace drive wheel rubber
Reset drive
Oil centre of drive spindle
Rethread and reset tensions to winder
Reduce winder tension
Reset tension unit or guide
Tighten tension
Re thread correctly
Slacken tension
Rethread correctly
Fit new bobbin
Close up the centre to accommodate the centre of
n
the bobbi
Reset the stop to allow winder to shut off at
maximum capacity without over filling the bobbin
Rest stop to allow winder to shut off later
Possible Remedy
Replace with correct spring
Realign tension unit
Reset or retime check spring
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