Troubleshooting

If a program doesn’t run you may check the following

Check Connections

1. Connect the EV3 brick to the computer and launch the LEGO Mindstorms programming software (IDE).
2. Make sure the robot is switched on.
3. In the lower left hand side of the IDE select Port View.
   1. Verify that all sensors and motors are visible.
   2. For sensors, users can check to make sure that Port View displays their current readings.
4. If a motor or sensor is not visible carefully disconnect and reconnect the cable for that device. A data cable should “click” when properly seated.
5. After reseating the cable check Port View to see if the motor or sensor is now displayed.

Check Motors and Sensors

1. If you suspect that a motor or sensor is not operating properly you can swap that part out for a different motor or sensor.
2. Sensor input can be checked by using Port View in the lower left section of the LEGO Mindstorms programming software.
3. Check that Motors are connects to lettered ports (A-D) and that any sensors are connected to a numbered port (1-4). The type of ports are not interchangeable.

Check Programming

1. Verify that all Motor and Sensor connections are specified with the correct port (i.e. if a device is plugged into a specific port that same port should be specified in the program).
2. Verify that your program was saved PRIOR to uploading it to the robot (this is one of the most common failures). Note: an * displayed next to the program name indicates the file is recently modified and not saved.