I am also a newbie but did you try disconnecting every single component and trying connecting the Arduino isolated.
The possibility is there, try this. Start by removing everything connected to the arduino then try this:Take these steps: Power off the board completely (remove the USB cable). Wait about 15 seconds.Hold down the Reset button, keep it held down (or, run a jumper wire from the RESET pin to the GND pin). Still holding down Reset, reconnect the USB cable. Start uploading a sketch that does not have this problem (I use the Blink sketch). I have seen this happen several times when I flood the serial output. An indication is the tx light is on. Try this several times, it does not always work on the first pass.Secret do not keep the console constantly busy printing. I put a 5 second delay in the setup so I can get control incase of a problem like this. Then remove all the motors from the 5V and power them from another power source, The 12 volt can be regulated to the 5V for the motors. Be sure to connect the grounds.Good Luck & Have Fun!Gil