If Youyou have the Arduino Uno with removable chip then try to remove the IC. Then plug it again and check the power on the icIC with a multimeter on pin 7 (+ positive) and pin 8 (- negative). If you are getting 5V there then you need to try to upload a simple blink sketch. If you are not getting the appropriate voltage then you can try to use a different wire to upload the sketch.
