70
30. Changing the base circuit board
Note:
The base circuit board is only exchanged as a complete unit.
Removal:
• Remove the mains lead from the mains socket and from the machine.
• Remove the detachable work support.
• Unscrew and remove the three fastening screws on the base plate.
• Tilt the base plate to the front.
• Remove the connection plug of 12-wire flat cable 4, remove 6-wire flat cable 5 and motor cable 6
from the circuit board (fig. 72).
Fitting:
• Set the new base plate complete against the machine.
• Mount three connection plugs 4, 5 and 6 on the circuit board.
• Fold the base plate against the machine and secure it with the three screws.
• After a running-in time of 10 - 15 min. check the adjustment of equal forward and reverse stitch length
in accordance with section 22 of the service manual.