Troubleshooting the 123 Robot

The following article will provide guidance on how to troubleshoot the VEX 123 Robot if you are experiencing one or more of the following issues:

  • The 123 Robot is not responding
  • The 123 Robot is not moving well, or driving straight

Illustration of a glowing VEX Robotics robot, used in the context of troubleshooting for VEXcode VR, highlighting key features and components relevant to Category 123: VEX Robotics and VEXcode VR Overview.


Updating the 123 Robot’s Firmware

A collection of icons related to VEX Robotics and VEXcode VR troubleshooting, illustrating various functions and features for users seeking assistance in the VEX Robotics ecosystem.

If your 123 Robot is not behaving properly, or at all, the firmware may need to be updated. The 123 Robot’s firmware can be updated using VEXcode 123, or the Classroom App.

Screenshot of VEXcode interface showing steps for updating robot firmware, used in troubleshooting for VEX Robotics projects.

To update the 123 Robot’s firmware using VEXcode 123, connect your 123 Robot to your device running VEXcode 123. If the firmware on your 123 Robot needs to be updated, it will begin automatically updating upon successful connection.

Image of a VEX robot with an updated design, showcasing various components and sensors, used in the context of troubleshooting VEX Robotics and VEXcode VR.

You can also use the VEX Classroom app to update your 123 Robot. To learn how to update your 123 Robot’s firmware using the VEX Classroom app, view this article from the VEX Library.


Removing and Cleaning the 123 Robot’s Wheels

Close-up view of the bottom wheels of a VEX Robotics robot, illustrating the design and construction for troubleshooting purposes in the VEXcode VR Overview category.

If your 123 Robot is not driving straight or turning accurately, the wheels on the bottom of the 123 Robot may need to be cleaned.

Close-up view of the bottom screws of a VEX Robotics robot, illustrating components for troubleshooting in the VEXcode VR Overview category.

To remove the wheels, first remove the four screws holding the bottom base plate in place. The screws should remain connected to the base plate after unscrewing.

Flowchart for troubleshooting VEX Robotics issues, outlining steps and solutions for common problems in VEXcode VR, designed to assist users in diagnosing and resolving robot malfunctions.

Next, locate the wheels underneath the base plate.

Diagram illustrating troubleshooting steps for VEX Robotics, featuring labeled components and potential issues to assist users in diagnosing problems with their robots.

Remove the wheels by lifting them straight up and out of place. Remove any dirt and debris from the wheels themselves, and the track where they were contained.

Flowchart for troubleshooting VEX Robotics issues, detailing steps and decision points to resolve common problems in VEXcode VR.

Once the wheels and the track they are contained in have been cleaned, the wheels can be replaced. When placing the wheels back into the 123 Robot, ensure that the gear on the wheel is on the same side as the gear in the track of the 123 Robot. The prongs on the wheel also need to slide into the grooves in the 123 Robot.

Diagram of the bottom groove of a VEX Robotics robot, illustrating key components for troubleshooting in VEXcode VR.

Once both wheels have been reinserted correctly, replace the base plate on the bottom of the 123 Robot and tighten the screws. Ensure the base plate is oriented in the correct direction, where the tab on the plate aligns with the groove in the bottom of the 123 Robot.


Hard Resetting the 123 Robot

Bottom left wheel of a VEX Robotics robot, showing troubleshooting details for maintenance and repair.

If your 123 Robot is not responding properly or not connecting to a device, it may need a hard reset. There is a small button hidden inside the 123 Robot near the left wheel when the 123 Robot is upside down and the Eye Sensor is facing upwards.

Flowchart for troubleshooting VEX Robotics issues, illustrating steps and solutions for common problems in VEXcode VR, part of the VEX Robotics overview.

To access the hard reset button, the left wheel needs to be removed. To remove the left wheel, follow the steps above in the ‘Removing and Cleaning the 123 Robot’s Wheels’ section of this article to remove the base plate and the left wheel. Once the left wheel has been removed, you will see a small hole containing a button next to the wheel track.

Flowchart for troubleshooting VEX Robotics issues, illustrating steps and solutions for common problems related to VEXcode VR.

Take a small item, such as the end of a paperclip, to press the button. You will hear a ‘click’ sound once the button has been successfully pressed.

Diagram of a VEX Robotics robot with a bottom-oriented design, illustrating troubleshooting tips for VEXcode VR. The image provides visual guidance for users in the context of robotics programming and problem-solving.

Once the button has been pressed. Follow the steps above in the ‘Removing and Cleaning the 123 Robot’s Wheels’ section of this article to replace the base plate on the 123 Robot.

For more information, help, and tips, check out the many resources at VEX Professional Development Plus

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