Is Your Arduino Fried? Let’s Find Out

Working with Arduinos is very simple when it comes to its user-friendly IDE and easy to use boards. But the real trouble begins when you accidentally make the wrong connections or supply the incorrect voltage to your board.

So, can you find out if your Arduino is fried? Yes, you can see if your Arduino is fried. Arduino boards are delicate when it comes to voltage and current surges—being the most common issue that users end up frying their boards.

Though not easy, there’re several ways to find out if your Arduino is fried. You need to scrutinize your board and pay attention to as many details as possible. This article will guide you through the steps to check it out.

What Does “Frying an Arduino” Mean?

“Frying” doesn’t mean to toss your Arduino into a frying pan and put it on the stove! It refers to the scenario when the Arduino board is electrically destroyed, and you can’t use them anymore.

If you experience a burning odor coming out of your board, that means your Arduino is fried.

Why Do People Fry Arduinos?

Well, nobody wishes to fry up their precious Arduino board and let the fun go down the drain.

People usually fry Arduinos by accident, by either applying the wrong voltages or making the improper connections.

Here are 6 of the most common causes users end up frying their Arduino board.

Cause #1: Applying the Wrong Voltage on The Input Pins

The operating voltage of most Arduino boards is 5V, while others operate at 3.3V. Meaning that if you supply energy to the input pins higher than the operating voltage, then you’ll end up frying your board because the voltage regulator diode will burn out.

Voltage regulator.

Most people think that the voltage regulator will take care of the excess voltage, but that’s not true. The voltage regulator only works for the barrel connector and the USB port.

Cause #2: Short-Circuiting

Another common practice that has destroyed many Arduino boards is short-circuiting.

Basics of short-circuit explained.

While working on a project which has a lot of output and input pins involved, you may end up connecting an output pin to another output pin or an input pin to another input pin, and that’s precisely where the trouble begins.

When two I/O pins are connected, and one is set to high, and the other is set to low, the most likely outcome would be that the pins will get damaged permanently because of excess current flowing through the pins.

Cause #3: Drawing More Current from The Output Pins

The maximum current that can be drawn from an Arduino is a fixed value that you can find in its datasheet.

Let’s consider the Arduino UNO board, for example.

According to the Arduino website, the maximum DC that can be drawn or supplied from/to an I/O pin is 40 mA. Therefore, if you bring more than 40mA by connecting a heavy load to your UNO board, it will damage your board permanently.

Similarly, there’s a limit to the maximum current you can draw from all of the output pins combined. Exceeding this limit would also damage your I/O pins.

Cause #4: Supplying the Wrong Voltage to The Vin Pin

In case you don’t want to use the barrel connector or the USB port to power up your Arduino, you can choose to use the Vin pin.

The Vin pin is connected to the voltage regulator present on the board, which converts any voltage up to 12 Volts to 5 Volts.

Meaning that if you supply the Vin pin with an energy more than 12 Volts, then you will end up frying the voltage regulator and, ultimately, your Arduino board.

Cause #5: Static Charges

Electronic devices are very sensitive to electrostatic charges. Therefore, they’re kept in anti-static packaging most of the time.

Arduino is well equipped to fight against electrostatic charges because it has an inbuilt diode that protects against static charges.

However, if the static charges affect the board for a long time, the diode may end up getting damaged.

Cause #6: Supplying Reversed Voltages

Applying 5 Volts on the ground pin and 0 volts on the Vin/5V Pin can also damage your Arduino board completely. That’s because you’re providing a high voltage to a pin designed for 0 volts.

The internal circuitry of your board will be damaged, leaving your Arduino board with irreversible damage.

This mistake sounds very silly, but when one is super stressed out while working on an Arduino project, one can make this mistake very quickly.

How to Find Out If your Arduino Is Fried?

Now that you know what the leading causes of Arduino boards getting fries are, you can easily find out if your Arduino is fried.

If you remember making any of the mistakes mentioned above, then you can quickly figure out whether your Arduino board is working or not.

In case you don’t remember making any of those mistakes, then you can check each of your Arduino’s components separately to determine whether they’re burn or not as follow:

  1. Power up your Arduino through the USB port, check the green power LED. If it is working, that probably means your board has not been fried.
  2. Check the 5V and 3.3V pins to see if they are providing the exact voltages by using a voltmeter. If these pins are providing the right current, this indicates that your voltage regulator has not been blown up.
  3. For further confirmation, you can power your Arduino using the barrel connector and then check the output of the voltage regulator.

If you don’t know how to use a voltmeter to check the voltages on your Arduino board, click here. This guide will ease the task for you.

Checking the board smoked protection diode.

  1. Check the diode (you’d need a multimeter with its knob set on the diode check position).
  2. Then, placing the probes on each side of the diode, you can check if it is working. The reading on your multimeter must be somewhere around 0.6 to 0.7 mV.
  3. If the voltmeter does not show any value, that means your diode is not working, and you need to get it fixed.

For a detailed guide on testing a diode using a multimeter, check this useful guide.

Another method to test your Arduino is to inspect your board for signs of burn such as black burn marks, inflated ICs, or unusual bumps on any of the components embedded in it.

Usually, when a component or an IC smokes out, it becomes inflated or becomes black. You can also try smelling your board to check for a burning smell.

How to Prevent Your Arduino From Frying?

If you’ve fried your Arduino and identified the reason behind it, then you have succeeded in achieving the purpose of this post.

To avoid frying your Arduino in the future, you need to take some necessary precautions.

  • Always double-check the connections you’ve made before powering on your Arduino board. Make sure there is no sign of short-circuiting.
  • Make sure you have not applied reverse polarity to power on your Arduino board.
  • Before connecting a load on the I/O pins, study its current requirements carefully. The amount must now draw more than 40 mA from a single I/O pin.
  • Always keep your Arduino board in a safe place, preferably in anti-static packaging, to avoid electrostatic discharge.
  • If using a DC adaptor to power your Arduino, always check its DC output rating mentioned on it. It must not be higher than 12V.
  • Please avoid using the 5V pin to supply power to your Arduino board because it doesn’t connect to the voltage regulator; hence the chances of frying your Arduino through this pin are very high.
  • Read the Arduino board specifications before using it in your project. Each board has different current, voltage, and power specifications, so it’s better to prevent and go through the technical specifications on the Arduino website.

Final thoughts

I am sure that by now, you have mastered the dos and don’ts to avoid frying your Arduino boards.

In case you’ve fried your Arduino board, you can also take a look at some tutorials or ask for recommendations at popular Arduino forums for ways to fix it.

In case you cannot repair your board, that means you need to buy a new one and take necessary precautions before using your new board. After all, being careful is better than being sorry!

Did you damage any of your Arduino boards, and I didn’t mention the reason in this article? What did you do to fix it? Let me know in the comment section below!

Wanna dig in more on this topic? Check out these awesome articles!

  1. How not to fry your Arduino? (
  2. Arduino Uno REV3. Check out its technical specifications (
  3. Arduino smoked diode repair / Fix USB power problem (YouTube).


Engineer and electronics enthusiast. Enjoys solving problems with electronics and programming.

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