My daughter played around with her aduino UNO, following a youtube tutorial.
Later we found that the builtin led not blinking anymore.
Also any blinking led projects using breadboard doesn't work.
Is the board fried?
There is a youtube video showing first project using a LED and connect it between the pin 13 and ground (directly without resistor). My daughter could have followed this example.
Power led works. Builtin LED works, just not blinking. Pressing reset button will blink the builtin LED three times.
Uploading sketch creates no error message
When you buy a new UNO board, it is running a program that blinks the LED. But when you upload a sketch to the board it overwrites that original program. For this reason, the LED will only blink if your sketch code causes it to blink.
Please try this:
Select File > Examples > 01.Basics > Blink from the Arduino IDE menus.
Select Sketch > Upload from the Arduino IDE menus.
Wait for the upload to finish successfully.
Do you now see the "builtin" LED on the board blinking at 0.5 Hz?
Then the LED and the pin on the ATmega328P microcontroller connected to it is still working.
Although it is a bad idea to leave out the current limiting resistor when connecting an external LED to a pin, you will probably get lucky and not have any physical damage to the board by doing that. So make sure to use the resistor in the future, but otherwise I wouldn't jump to the conclusion that things are broken. The lack of activity on the LED is more likely a problem with your code.