Actually I have tried this with my Arduino uno R3 clone but the method is same for the original board too.
Step 1: What You Need?
Step 2: Disconnect Power
Also remove all connections and shields from the board.
Step 3: Connect Jumper Wires
2.)Connect a jumper wire from TX pin(digital pin 1) to the RX pin(digital pin 0). (white wire in photo)
Step 4: Connecting Board to PC
Start terminal application like serial monitor after selecting your port.
Send data by typing.Whatever you write should be echoed back.
If exactly what you write is echoed back then the board passes the test.And so the host computer hardware driver,USB cable,and USB to serial converter are all working.
Step 5: If Nothing Echoes Back!
* You have the correct com port.
* Try a different cable.Some cheap USB cables only have power wires and not data wires.
* Check the device driver for the Arduino is installed .