TM 10-3530-207-14
Table 3-1. Operator troubleshooting - continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
DARNING SEWING MACHINE
Step 2. Check that bobbin case is seated in rotary-sewing hook correctly.
Seat bobbin case correctly (para. 2-12f).
33.
PRESSER FOOT PRESSURE REGULATOR THUMBSCREW IS HARD TO ADJUST .
Presser foot may have been lowered before change was made in the pressure setting.
a.
Raise presser foot with hand lifter.Decrease pressure on presser foot by turning the
pressure adjusting thumbscrew counterclockwise. Lower presser foot and adjust
presser foot to the desired pressure for the fabric being worked.
b.
If presser foot pressure cannot be increased or decreased, notify next higher level of
maintenance.
34.
MACHINE VIBRATES.
Step 1. Check that machine-to-table mounting screws are tight and check that table is on a flat
hard surface.
a.
If mounting screws are loose, notify next higher level of maintenance.
b.
Relocate table to flat, hard surface, if necessary.
Step 2. Machine motor drive belt is too tight.
Adjust belt (paragraph 3-10).
Step 3. Machine drive pulley or balance wheel out-of-balance, loose, or installed wrong.
Notify next higher level of maintenance.
35.
LAMP DOES NOT LIGHT.
Step 1. Check lamp ON/OFF switch.
Set lamp ON/OFF switch to the ON position.
Step 2. Check that lamp light cord is plugged into input power outlet.
Plug in light cord into power outlet, if necessary.
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