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.
Hi,Please read the first post in any forum entitled how to use this forum.http://forum.arduino.cc/index.php/topic,148850.0.html then look down to item #7 about how to post your code.It will be formatted in a scrolling window that makes it easier to read.
How are you powering the Arduino if you have the alim (powersupply??) disconnected?
What color wires are you connecting to on the power supply? A schematic would be a huge help in understanding what you're trying to do. It sounds as though you're connecting to the auxiliary supply which cannot supply the required current.
Some older computer power supplies must have a minimum load on one or more outputs to maintain output voltage. The typical load is a 10 ohm, 10 watt resistor from VCC/+5V to GND.
I'm using a red wire of the PSU to supply power to the Arduino (5V and up to 20 A), and it is connected to the jack plug.
It would also make a lot more sense if your circuit was connected directly to the 5V power supply rather trying to run all that current for your sensors and servos (or whatever they are) through the Arduino. That is a really bad idea.
So the center pin of the power barrel jack is what you've been calling VCC?