Answered: VEXnet joystick battery dead... re-tether?


While I was testing some code, the joystick lights went red (indicating low battery), so I went ahead and changed out the batteries.

Now the robot doesnt seem to want to interface with the Cortex Microcontroller.

I’ve tried to re-tether them via the USB cables, but it doesnt seem to be working. (as per these instructions here:

As of now, the joystick robot blinks green slowly and the Vexnet and Game lights are blinking amber quickly…

-edit- now all LEDs on the joystick are red.

Can anyone point me in the right direction?



Do you still have red LEDs on the Joystick?
If so, please try a fully charged battery.

Once you connect the new battery power-cycle the Joystick and the Cortex and they should link-up without the need of re-tethering.

Give it a try and let me know if it works.


put in new batteries, still no connection.

controller blinks green, goes all red, and then repeats.

microcontroller vex and game blinks steady yellow -> all red, etc

any ideas?


i re-downloaded the master code to the controller, and now i am able to control the robot with the usb cable connected from joystick -> cortex microcontroller…

however, if i want to do wifi, the controller doesnt even light up.

Have you even been able to power-up your Joystick with just batteries?

When I turn on the power to just the joystick (with fresh AAA batteries) nothing happens, no lights. nada.

Very strange…
According to your first post, you were getting power to the Joystick with just batteries… correct?

Yes. It was at one point. But now its unresponsive.

However, I am able to control the robot still via USB A-A cable.

Not the best way to do things, but it will do.


You should still be able to control your robot through the VEXnet Keys if you use the VEXnet Joystick Power Adapter

it functioned wirelessly with the keys before… its just not doing it now.

In order to user the VEXnet Keys you will need power on Joystick and Cortex.
If you are having power issues on the Joystick the VEXnet keys will not connect.
You should still be able to power up your Joystick with the VEXnet Joystick Power Adapter.


why would I need to purchase a power adapter, if the joysticks were functioning perfectly before I encountered this issue?


All of our products have a 90-day warranty.
If this Joystick is still under warranty we may be able to replace it.
If its out of warranty you can get an RMA number and mail the unit back to us for troubleshooting (repair fee may apply).


Did you double check the way the batteries are installed in the Joystick – are they all orientated the proper direction? Do you have a voltage meter so that you can measure the combined voltage of all the batteries when they are installed in the Joystick?