I am making an open source 3d printer as my minor project for college but i am stuck as my motors are not functioning properly, either they are just vibrating at their place or not working at all. I am using Nema 17 motors with A4998 stepper driver and Aurdino Mega 2560. I googled how to know the correct Tx and Rx terminals, as I thought it was problem, but now my motor is not functioning at all when i run it individually with the Arduino, power supply and stepper driver. Can you please tell me how I should get my motors to run?

Also the motors are local and so are most of the components.