Schwinn S350 LED throttle illuminates green and red when turned on

Hello All,
My daughter had a Schwinn S350 that she has out grown and has been handed down to my son. Now the problem is that I have replaced the batteries and all went great for about 2 weeks. Now after batteries were recharged and turned on, both the green and red LED lights illuminates on the throttle control and the scooter will not run. Both battery voltages are correct, and not sure how to proceed from here. Any help would be greatly appreciated.
Thanks