Replace the Front Wheel Sensor

To replace Junior’s front wheel sensor, you’ll need a Phillips head screwdriver, the flat head screwdriver that came in Junior’s box, and a new wheel sensor.

Before starting any repair on Junior, turn his side power switch OFF and remove his dustbin.

Then, flip Junior over onto a flat surface and remove his side brush using the flat head screwdriver. And remove the main brush.

Keep all removed screws and parts safely aside, as they may be needed for later re-assembly. Use a Phillips head screwdriver to remove the 7 screws on Junior’s underside that hold him together.

There are 5 screws along the edges of Junior: One screw on each side of the front wheel.

One screw to the right of the main brush motor. And one screw on each side of the dustbin. The final two screws are in Junior’s brush compartment.

Junior’s cover is no longer secured, so hold the top and bottom together as you carefully flip him back onto his wheels.

Grip Junior’s cover from the back and lift up to expose the mainboard.

Slide the power inlet down and tuck it somewhere safe to avoid compressing its wires.

To detach Junior’s cover completely, disconnect 4 circuit plugs:
Two at the lower edge of the mainboard, near the wheels and two more at the top edge, near the bumper.

Junior’s cover is now completely detached and can be set aside for the rest of the repair. To remove the front wheel sensor, you must first uninstall the mainboard.

Disconnect all remaining 11 circuit plugs from the mainboard. Press the small tab on each circuit plug and pull to disconnect.

Remove 3 screws on the mainboard. Keep them aside for later reassembly.

Then, lift the mainboard out of Junior.

Remove the two screws securing the sensor onto Junior. Keep these screws closeby for later reassembly.

Remove Junior’s front wheel sensor from underneath him. Next, grip the front wheel with your hand. Pull it up, using a screwdriver for leverage if needed, and the wheel will pop out.

Then, place the new sensor on the front wheel.

Place the sensor and wheel underneath Junior so the circuit plug goes through the opening and into Junior’s interior. Then connect it to the mainboard.

Re-install the two screws and you’re ready to replace the mainboard.

Align the holes with the 3 screw posts on Junior’s interior.

Ensure that the mainboard sits flat before re-installing the 3 screws. One screw goes in the middle of the mainboard, one in the top corner, and one in the lower corner.

The order of plugs on the left side of the mainboard, from top to bottom, is:
A small plug with black and yellow wires, a plug with two pairs of twisted wires, a plug with multi-colored wires for Junior’s left wheel, and one empty space.

For now, the bottom of the mainboard will have two open spaces on the very left.

Then, the order from left to right is:
A small circuit plug with a red wire, one more open space, a small plug with yellow wires, and lastly, a plug with multi-colored wires on the very right.

The order of plugs on the right side of the mainboard, from top to bottom is:
A plug with black and orange wires for Junior’s power inlet, and a wide circuit plug for Junior’s power switch.

The order of plugs at the top of the mainboard, from left to right, is:
A small plug with red and green wires, a wide plug with multicoloured wires, two empty spaces for now, and a small plug with black and orange wires in the top right corner.

Now you’re ready to begin re-attaching the cover to Junior’s mainboard.

Reattach all four circuit plugs connecting Junior’s cover to the mainboard.

There are two that connect to the top edge of the mainboard. And two more that connect to the bottom edge.

Remember to slide the power inlet back into its space on Junior’s cover. Align the cover’s edges precisely. Then, flip Junior over onto a flat surface.

Re-install the main and side brushes using the flat head screwdriver.

Replace the dustbin before your next use and Junior is completely re-assembled.

Turn the side power switch back on and congratulations! You’ve just replaced Junior’s front wheel sensor. Happy cleaning!

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