I am trying to not only build but understand how this project works. Its a sentry gun. I am new to electronics and when I built it my diode burnt up! I used a 1n4004 diode. And a 6v airsoft gun at least one that takes 4 AA's battery's. At first the gun made a noise and did not fire. I think it's not getting enough current. I went into the program and put the gun on full auto and it still just made a noise but a continuous one. Then I substituted the 4 AA's for a 6V 3700 mAh battery. The gun still did not fire then the diode burnt up . This was probably a dumb thing to do but I'm new to this sort of thing. even before I switched battery's It smelt like something may be burning. Obvasly I'm not shore but I think the mosfet is wrong too because like I said the gun did not fire it just made a noise for a second. I have the lights, switches and servos all working. Its just the gun firing that's giving me troubles. Thank you for any help. Hear is the schematic.