VEX EXP Controllers

What should I do if I cannot turn on my controller?

Is your controller a new controller or has it been used before?

Is there a battery installed in the controller? You can check by removing the cover on the back of the controller
What happens when you connect the controller to a USB charger? Does it charge? Are you able to switch it on whilst it is connected to the USB charger?
If it will turn on when connected, does the controller stay on when removed from the USB charger?