Husqvarna Automower 420 Workshop Manual page 31

separately. The front sensor circuit board must be
replaced as a unit.
1. Remove the body. Refer to
the body on page 20 .
2. Remove the upper chassis. Refer to
install the upper chassis on page 20 .
3. Disconnect the cable.
4. Remove the screw and the holder for the front loop
circuit board.
5. Pull up the front sensor circuit board.
6. Install in opposite sequence.
6.18.8 To replace the rear loop sensors and tilt
sensor
The rear loop sensors and tilt sensor are integrated in
the main circuit board. The sensors cannot be replaced
separately. The main circuit board must be replaced as
To replace the main circuit board on
one unit. Refer to
page 28 .
6.18.9 To replace the lift sensor circuit board
The magnet on the joysticks must be installed correctly
for the correct operation of the lift sensors. If this is not
the condition, parts of the front joystick must be
To replace the front joysticks on page
replaced. Refer to
25 .
1. Remove the body. Refer to
the body on page 20 .
2. Remove the upper chassis. Refer to
install the upper chassis on page 20 .
1191 - 001 -
To remove and install
To remove and
To remove and install
To remove and
3. Disconnect the cable from the lift sensor circuit
board.
4. Push the clip and remove the lift sensor circuit
board.
5. Install in opposite sequence.
6.18.10 To replace the front collision circuit board
The magnet on the front edge underneath the body must
be installed correctly for the correct operation of the
collision sensor. If this is not the condition, the magnet
holder which is a part of the charging plate installation
must be replaced. Refer to
plates on page 33 .
1. Remove the body. Refer to
the body on page 20 .
2. Remove the upper chassis. Refer to
install the upper chassis on page 20 .
3. Disconnect the cable from the front collision circuit
board.
To replace the charging
To remove and install
To remove and
Repair instructions - 31