Wires D10 Burned (4 replies)

Hi

I've just assembled my first prusa i2 with ramps 1.4, arduino mega anda a power supply 12V 30A. I printed for the first and a second time but when i pressed to print the third time the wires that connect d10 to the resistor just completely burned and with smoke coming out. Now the led4 (wish i assume correspondes to d10) is constantly turned on. Can anyone give some help please?

Thanks