Arduino Micro defective?

Development Tools IDE 1.x
1

Hi alltogether,

dont know if this is the right forum or not to ask this question, but I think it fits best in here.

I have a project, with two identical circuits on two breadboards. Now, I have two Arduino Micros. And my program runs on one Arduino (on each of my breadboards) without an error. BUT the program wont run with my other Arduino (on nor of the breadboards).

What can be the cause of this behaviour?

2

I guess I've found something.

The arduino wich works with my circuit delivers somewhat around 3.5V on VIN when powered via USB.
The other one does not deliver anything.

Is this somthing i can configure on my arduino??