Connecting to PC issues

Hi all, I am new to 3d printing and still trying to fully calibrate my printer.

I have built my own 3d printer, it's based off the designs of a prusa i3. I am using an Arduino 2560, RAMPS 1.4.
The printer is working very well on it's own but I would like to be able to connect it to the PC. Makes calibrating much easier and also easier to print directly from PC.

When I connect it to the computer and then turn the power supply on the arduino and ramps turn off. (I could also smell burning things, but apparently everything is working as normal so probably nothing was damaged.)

Any help appreciated.

If you can smell burning things, then something do not sounds right, you have double check it. As it seems the board get to much Voltage hence it auto turn off!?