tablet only works when plugged in with usb charger

My tablet only works when a usb charger or external battery is connected. The DC charger doesn't work. The battery will say 100% but I unplug it it dies. When I try to use a usb data cable to connect to PC it shuts off. It will work when plugged into the PC with a power usb cord only. If I try to use a data cable it won't power on. What could be the cause and a fix? My tablet is also rooted by the way Android 4.4.1 I think.