My old sprint LG viper wont charge

I recently found my old phone i had back in 2012 and i wanted to see if it still works so i tried charging it and i dont think its taking a charge. When i first plugged it in the bottom buttons started flashing and now its not even doing that, its just a black screen. I took a toothpick and scrapped inside of the phones usb port and that didnt work. I tried 2 different chargers and multiple wall sockets. So can anyone help me?