Arduino robot COMPLETELY stopped working and now will not connect to the compute

Id received an arduino robot (which came with NO instructions or other information) so I went online to see if I could find any information. I found a reliable source, copied the sketch exactly and verified/compiled it,no errors, I made sure Ihad selected the right port and board, all was good, but when I went to upload it to the board, the LCD screen on the robot went blank and now the robot will not connect to the computer. Any ideas as to what happened?

We need more info, like when you connect it to usb, does it receive power, what happens when you turn it on from external power?