I'm facing a problem with a project that involves multiple temperature readings, motor control, and several relays. I'm using an Arduino mega 2560, powered by a computer alimentation (300 W), in 5V.
The problem is, that when I connect the VCC pin (of the Arduino) to my circuit, the alim block shuts down immediatly. If the Vcc pin is not connected, the alim runs normally, and the arduino is powered correctly. And if I do the opposit, if I disconnect the Gnd and connect the Vcc, the alim runs normally as well.
I tested my circuit with a multimeter, did a continuity test between its Gnd and its Vcc, to check for short cut, and got no continuity. I checked the resistance betwen those, and obtained about 3 kOhms, which seems normal considering that all resistors are put in parallel (altough I didn't do the maths ^^).
The motors I'm using are servo (7 of them), they are "detached" when not used, I'm also using 12 relays (dispached on 2 plates), 9 thermistors, and a DHT 22 sensor.
So the question is, why does the alim shut down ? Could there be a short cut else place ? Could it be a flaw in the chip ? Or is there another problem ?
Any help would be appreciated