Husqvarna Automower 420 Technical Manual page 73

3. Disconnect the cable from the lift sensor
circuit board. Note: Always pull the
connector and NOT the cable.
4. Remove the lift sensor circuit board by
carefully bending up the snap-on fasteners
and lifting out the sensor circuit board.
5. Unscrew the 2 screws (Torx 20) which
secure the holders for the front sensor
circuit boards.
6. Fit the new sensor circuit board and
reconnect the cable.
7. Refit the chassis and body.
5.18.4 Front collision sensor
The magnet on the front edge underneath the body
must be fitted correctly if the collision sensor is to
work. If this is not the case, the magnet holder which
is a part of the charging strip mounting must be re-
placed. Refer to 5.6 Replacing the charging strips
on page 64.
To replace the front collision sensor circuit board:
1. Dismantle the body, see 5.2.1 Dismantling
the body on page 59.
2. Dismantle the chassis, see
5.2.2 Dismantling the chassis on page 59.
3. Disconnect the cable from the collision
sensor circuit board. Note: Always pull the
connector and NOT the cable.
4. Remove the collision sensor circuit board by
carefully bending up the snap-on fasteners
and lifting out the sensor circuit board.
5. Fit the new sensor circuit board and
reconnect the cable.
6. Refit the chassis and body.
5.18.5 Rear collision sensor
The magnet in the right rear collision column must
be fitted correctly if the collision sensor is to work If
this is not the case, the front collision column must
be replaced, see 5.22 Replacing the rear collision
columns on page 76.
To replace the rear collision sensor circuit board:
1. Dismantle the body, see 5.2.1 Dismantling
the body on page 59.
2. Dismantle the chassis, see
5.2.2 Dismantling the chassis on page 59.
5. REPAIR INSTRUCTIONS
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