Scooter stopped suddenly... But has New batteries

Hi guys, I bought my daughter a used scooter. Batteries were shot. So I just bought 4 new 12 volts. (Ugggghhh). Ran great for a couple days then it just suddenly quit. Batteries didn't die. But I thought maybe they did. Still... It didn't do anything after a charge. So I had to manually charge them. They were now totally full. Still didn't work. So I then I thought charging port. But I get voltage through the cables when it's plugged in. So now... I don't know. There a couple amp looking things in there. I wonder if they are shot. I have the whole thing torn apart right now lol. Does anyone have any idea as to what is wrong or what I can do to find out?

Thanks,

Cam

loose wire? maybe a fuse? check throttle wire