Pfaff EXPRESSION 2014, Service Manual, Page: 90 / 112

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38. Changing the buttonhole sensor
Note:
The buttonhole sensor is only exchanged complete.
Removal:
●
Remove the machine's mains lead.
●
Remove the needle and presser foot.
●
Remove the folding cover.
●
Unscrew and remove both torx screws from the housing insert.
●
Remove the housing insert.
●
Raise both lugs 1 slightly and remove the facing panel of the front housing panel.
●
Place the machine on its back.
●
Unscrew and remove the three screws in the base plate.
●
Tilt the base plate to the front and remove both connection plugs 3 and 4 from the circuit board
(fig. 108).
●
Unscrew and remove both screws 5 from the free-arm cover (fig. 109).
●
Bring the feed-dog lowering mechanism into its normal working position.
●
Disengage both feed regulators 6 using a small screwdriver (fig. 109).
●
Remove the cable clip.
●
Remove connection plug 16 from the circuit board of the front housing panel and pull the cable
downward (fig. 110).
●
Remove the free-arm cover from the housing to the left.
●
Remove connection plug 13 from the circuit board of the front housing panel and pull the cable
downward (fig. 110).
●
Remove cable guide 20 (fig. 109).
●
Dismantle buttonhole sensor 138 complete with the spring.
Fitting:
●
Install buttonhole sensor 138 complete with the spring.
●
Insert the cable with cable guide 20 in the housing.
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Turn the machine upside down.
●
Place the cable, using a spring hook, between the motor and the housing wall.
●
Mount connection plug 13 on the circuit board of the front housing panel (fig. 110).
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Put the machine in its working position.
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Mount the free-arm cover carefully and secure with both fastening screws 5.
●
Bring the feed-dog lowering mechanism into its normal working position.
●
Engage both feed regulators 6 (fig. 109).
●
Turn the machine upside down.
●
Place the cable, using a spring hook, between the motor and the housing.
●
Mount connection plug 16 on the circuit board of the front housing panel (fig. 109).
●
Attach the cable clip.
●
Mount both connection plugs 3 and 4 on the circuit board of the base plate (fig. 108).