Pin 13 LED

Thanks for everyone that has responded so far. I uploaded a video jst so you can see exactly what im talking about. My biggest concern is why the sketches would only run if I select the "Serial Monitor" after uploading and why the sketch doesnt seem to retain itself in the memory. Its my first time using Arduino and im not sure if this is normal or a software/hardware problem? Appreciate the help

Here it is: http://www.youtube.com/watch?v=lmvUiODvxnM

What you say is not consistent... May be its all the things that happened to you one after the other? What is the CURRENT state now? - You can upload sketches? - They do not start-up immediately after loading, but only after you press reset? - .. or start the Serial Monitor?

The LED blinks because when you buy an Arduino board, it has the 'Blink' sketch installed on it.

If it is still blinking after you thought you had uploaded your sketch, then your sketch has not really uploaded.

The new sketch should start right after it is uploaded to the arduino, unless there are something in your code that waits for the serial stuff.

What is it you are uploading to it?

Thanks for the response... Sorry if it wasnt clear. Here's what happens:

When I plug in the Arduino, the LED (L) constantly flashes. (once every half second, it seems)

I then try to upload the Button sketch. It states that the Upload was successful. I wait for a while and nothing happens. (LED still blinks constantly) Only when I select the Serial Monitor does the LED stop blinking and the Sketch to start working.

When I close the Serial Monitor, it seems to erase the sketch and the LED starts to blink constantly again.

Is this normal or maybe a setting or hardware issue. Im newbie to the Arduino. Thanks in advance for taking the time to help me

As I said before, this is not consistant.. A miracle???

A rational explanation: A defect in the bootstrap loader, that does not start the user program after reset, but goes into an internal blink loop?

Or can it be that not LED 13 is blinking but the XMT LED?

I then try to upload the Button sketch. It states that the Upload was successful. I wait for a while and nothing happens. (LED still blinks constantly) Only when I select the Serial Monitor does the LED stop blinking and the Sketch to start working.

Opening the Serial Monitor resets the Arduino. It begins re-running the same sketch that it was running.

"the Button sketch"? There are hundreds of sketches that you might be referring to. Can you be more specific?

Probably the Button example in the IDE. Running this sketch without the hardware (pull down resistor and switch) can cause the LED to blink at random intervals as noise moves the state of the input pin, its usually not regular and may not happen at all.

I uploaded a video to show my problem. Hopefully it clarifies what my concern is. I modified and included a link at the original topic question above. Thanks again

That video shows an LED attached to pin 13, with no current limiting resistor. That's a good way to destroy the Arduino.

There a lot of old tutorials out there that have never been updated from the days when Arduinos had no LED and a current limiting resistor built in. Entirely unnecessary nowadays since they have a built in LED and current limiting resistor on Pin 13 anyway.

I'd say theres something sadly wrong with the bootloader from the evidence presented so far.