18 Husqvarna service manual 104 72 30-26
Switch for the presser foot lift
In the sewing head there is a little switch that close when the presser foot is being lifted.
Then you cannot sew and a humming sound and flashing displays warns.
If there is anything wrong with the switch the machine can sew.
The function of the switch can be checked with a multi-range instrument at the lowest -
range by measuring between the two pins of the plug.
Lifted presser foot = 1 .
Lowered presser foot = 0 .
If the values are correct the fault is inside the circuit board or the connection between the
circuit board and the LCD board.
(Exceptionally the fault can also be inside the LCD board).
Buttonhole meter
Check the functions according to directions for use.
Inside the buttonhole meter there is a potentiometer that
is influenced by the measuring wheel (A).
The function of the buttonhole meter can be checked by
a multi-range instrument (-measuring).
When the measuring wheel (A) is turned a value
between 0.4 - 10 k is obtained.
If the values are correct the fault is inside the circuit
board or the connection between the circuit board and
the LCD board.
(Exceptionally the fault can also be inside the
LCD board).
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