arduino disconect

Hello, i have done a little project with arduino uno, a led lamp and blynk app just like on this video Internet Of Things : Arduino + Blynk - YouTube. what happens if i disconect the usb cable and i turn of the laptop? what should i do to make it work again?

That is a bad tutorial!
The LED needs a current-limiting resistor.

If you disconnect the USB cable, the Arduino goes dead.
If you re-connect the USB cabble, the Arduino comes alive again.

.

Dandelion1994:
what happens if i disconect the usb cable and i turn of the laptop? what should i do to make it work again?

Connect the USB cable and turn the laptop back on.

Thank you so much for your answer but my question is, it will work again or i have to upload arduino for the second time.

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