Arduino turns off randomly??

Im A TOTAL newbie so hope im not asking anything too newbie-ish, but I really need help.
It seems that if i use more than 1 pin in the power section next to the analog the arduino turns off, these specific combinations turn it off:
5V & Ground (either of the gnd pins)
Ground & Vin pins,
Please help I need to be able to use to pins :-/

Which Arduino board do you have? How are you powering it? What are you powering off the 5V supply? The Vin supply? How have you got that wired up?

wow thanku for replying,
ok i have the arduino duemilanove and powering it by usb, Im not actually using the Vin pin (just wanted to see if it also caused the issued).

Iv got the arduino hooked up to a bread board with some leds and a push button switch, pin 7 to push button, 6,9,10,11 to the leds, and then ground and 5v to power the whole thing, but when connectin the 5v and grn the board turns off

5v and ground should NEVER touch directly... you never want to feed 5v into GND or vice versa..

But from what you've explained.. it's really hard to tell what it could be..

Do you have resistors on those LED's? Are all the LED's grounded? What about your pushbutton? Does it have a pull-up or pull-down resistor?(Internal or external) And what's the other side of the switch connected to?
GND ---> SWITCH ---> pin 7
5V ---> SWITCH ---> pin 7

It sounds like it's shorting out to me. But it could also be a "brown out" which means it doesn't have enough current so it resets. But that's probably won't happen, UNLESS, you forgot all your resistors on your LED's, forcing too much current out of the chip. (Or the leds are just way too big for the Arduino to power without a transistor or something of the sort)

hmm -
thats how iv connected it
hmm u may be rigth about the transistor tho.

If the diagram is correct.. you've got it hooked up way wrong. lol

On the switch, you're hooking up the GND and 5V directly... so that's the short I was talking about.

But regardless, with your LED's... uh, change that. lol The shorter end of the LED (also, the flat part of the LED) is the GND (-) that's got to goto GROUND directly.

The longer pin is the pin you want to connect to the Arduino pins, PIN7 ---> RESISTOR ---> + of LED

For example:

And your switch is hooked up wrong.. here's an example how to hook that up:

Thankyou very much CaptainObvious, ure a star

I do my best, lol :sunglasses: