Hi,
I have the Arduino Uno starter kit with Arduino uno R3. I have managed to load the blink sketch but the onboard pin 13 LED does not blink. If I connect an LED to pin 13 and GND it blinks, so it seems the program is working but the onboard LED is faulty. Do I have to replace the arduino or could something else be the problem?
And you are using a current limiting resistor i hope.
If not and it does blink, has the pin been defined as an output ?
Just because the LED isn't working, i wouldn't ! check to see if the cathode of the LED is actually connecting to GND with a multimeter. The Anode passes through a 1K (in my case a triple channel) resistor. It is always possible that a solder connection has broken and if you re-melt it it may work again just fine.
Your topic was MOVED to its current forum category which is more appropriate than the original as it has nothing to do with Installation and Troubleshooting of the IDE
I used a 220 ohm resistor as a current limiter.
I checked the onboard LED. One side is connecting to GND. The solders look OK. My hands are not steady enough for me to try to re-melt the connections.
It is probably not the LED itself that is the problem. There is a buffer between pin 13 and the LED (on a genuine Arduino) it is more than likely that this buffer is faulty in some way.
Send some pictures of the Arduino, around the spot where the onboard LED is.
Please photograph both sides of the board.
Essayez de passer le bout de votre fer à souder sur les deux bornes de la LED intégrée.
Ça devrait ressouder ce composant.
The back of the board is different from the R3 I have. Mine has an all white back. There looks like there is no physical damage or bad soldering, but not very many faulty components show up as physical damaged, unless they have suffered a great deal of abuse.
Can you put in a slow blink program on pin 13, and measure that the voltage on the pin changes. The look at the voltage across the LED, if it is not changing then it could be a short circuit LED or a blown driver buffer, that is the very small surface mount chip next to the LED.
Remove all power and then try an measure the resistance of the LED with the leads of your meter first one way and then the other. The actual measurement is not important, but with the leads one way round you should see a pin prick of light and that indicates the LED is working.
Unless you REALLY NEED the on-board LED why bother? Just drive any LEDs from the digital pins.
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