My charger for the venue 11 pro has broken.  When i plug it into the wall the light comes on but once i plug in a usb cord (tried several different functioning usb cables) the light on the charger turns off and it will not charge anything. So im trying to find a replacement but havent been able to, at least not on the dell website or from a reputable seller. Please advise where i can find a replacement charger. 
thank you.