So, after while of using it, my arduino started behaveing wierd. The integrated LED burned out for unknown reason and I atteched another external (whithout a resistor) to pin 13. It was working quite well, the light came out normal and solid, but after while the LED started blinkig like a strobe, as if I had put a delay under 200ms . The problem is that I havent. It blinks interupted for the amount of time I have put in and then stops. I have checked the pin with a voltmeter and there seems to be something strange. I get 0V and 4,5V for 2-3 times and after that I get some other different voltages. For example 0V, than 1,2V, than 4,5V, than again 0V, than this time 2,3V, and after that 4,5V. And this happens till it reaches the maximum of 4,5V and starts all over again.
Is this normal ? Am I getting this wierd blinking, because of the LED, or have I burned my arduino ? Do you get the same results when you attach a voltmeter to your arduino, while using the Blink example?