Arduino Not Turning On? Here’s What to Do

Many times working on my projects my Arduino board wasn’t turning on. If you’ve had a similar problem, then here’s the right guide for you.

Is your Arduino not turning on? Here’s what to do: There are four ways with which you can power on your Arduino board:

  1. Connecting it to the USB port
  2. Using the barrel connector
  3. Utilizing the Vin pin
  4. Using the 5V pin

Arduino is easy to work with, but sometimes, these boards can give you a tough time when not turning on. Most people give up and buy a new board, but you won’t have to after reading this article to solve this problem.

Why Is Your Arduino Not Turning On?

If your Arduino board is not turning on even though you’re supplying power to it, this means there’s something blocking the energy from reaching the microcontroller chip.

There can be many factors leading to this situation. Below are the most common causes:

#1. Problems with the USB Port

The reason why your Arduino board isn’t turning on when you connect it to the computer via its USB port is that there’s a problem in this connection.

Either the USB port on your Arduino board isn’t working, or the connecting cable is faulty. Meaning the power from your computer’s USB port is not reaching the microcontroller chip because the USB port is disabled, or the connecting cable is unable to transfer power.

To find out if this is the culprit behind the problem, try turning on your Arduino using the Vin pin. If it turns on, that means there is a problem with the USB cable or the USB port itself.

#2. Burnt Diode

Another reason why your Arduino board isn’t powering up is that you might have fried the Schottky diode (see image) present on the board. This might happen if you’ve accidentally shorted the board, which leads to an influx of extra current in the diode, causing it to burn out.

Schottky diode.

If you look at your Arduino closely, you will find a black colored diode embedded on your Arduino board. In case it is fried, you’ll notice a bump on the diode.

You can also check if the diode is working using a voltmeter.

Set the voltmeter knob on the ‘Ohm’ symbol and place the knobs on each side of the diode. The meter is supposed to show a value between 0.5 to 0.7 volts since it’s the standard voltage drop of a diode.

If your voltmeter doesn’t show any value, that means the diode is fried.

#3. Damaged Voltage Regulator

The voltage regulator present on your Arduino board regulates the input voltage and brings it to 5 Volts. In case you’re using the barrel connector to power up your Arduino, it will take the high input voltage and bring it down to 5 Volts, suitable for the Arduino board.

Voltage regulator.

If you’ve somehow damaged the voltage regulator, then your Arduino board won’t turn on when you connect it to the power supply using the barrel connector.

To check if the voltage regulator is damaged, look at it closely. If you notice a bump or a swelling on it, that means it has been damaged.

Here you can also use a voltmeter to check the input and output voltages of the regulator.

When you connect the Arduino to a 12V power supply using the barrel connector, the input to the regulator must be 12 Volts, and the output must be 5 Volts.

If the voltage regulator is damaged, that means it won’t produce the required voltage to power up the Arduino board.

Here’s what to Do if Your Arduino is not Turning On

Once you’ve successfully identified the reason why your Arduino isn’t turning on, then move on to fixing it choosing your solution as described below.

Solution 1: Get a New USB Connector

If the USB connector is the reason why your Arduino isn’t turning on, then you need to get a new connector as soon as possible. That would be the most natural solution to the problem.

Solution 2: Replace the USB socket

You might have to replace the USB socket on your Arduino port if that’s the reason why your Arduino is not turning on.

To do so, you will need a similar USB socket, and I’m sure that you can find it in one of the old electronic items present in your house.

In addition to that, you might need a soldering iron, a solder wick, and a sucker.

Using the soldering iron, carefully melt the solder that’s sticking the USB socket to the board and using a sucker, remove the solder. This will loosen the socket a bit. Keep on doing so until the socket comes off completely.

Then, grab the new USB socket and solder it carefully, making sure to connect its pins on the right spot.

If you’d like me to show you a video of this process, just let me know in the comment!

Solution 3: Replace the Fried Diode

In case you have fried the diode on your Arduino board, then buck up to replace it with a new one.

All you need is a soldering iron, a solder wick, a sucker, and a new diode.

Make sure you are using the same diode that is present on your Arduino board. You can check the diode specifications for your Arduino board on the datasheet from the Arduino website.

How to replace the diode?

  1. Remove the fried diode off your Arduino board.
  2. Press the tip of the soldering iron near the diode’s legs so that the solder melts down.
  3. Use the solder sucker to get rid of the solder from both sides of the diode. Keep on doing so until the diode comes off.
  4. Solder the new diode on the board but make sure where to place the positive and negative ends of the diode. If you solder it the other way around, your Arduino would still not power on.

To help you out to follow these steps, here there’s a tutorial on how to replace a fried diode on an Arduino Nano board.

You can use the same method for other boards as well.

Solution 4: Replace the Damaged Voltage Regulator

If the solutions mentioned above did not solve your problem, then this one might do the job.

Replacing the voltage regulator chip on the Arduino board needs a lot of attention. It would be best if you’re sure that you’re replacing the chip with the same one.

Make sure that the chip regulates the voltage to 5 Volts and not more than that, or else your Arduino board might start to heat up, and that would lead to a deteriorated performance.

Use the same tools as in the previous section – a soldering iron, solder wick, solder sucker, and, of course, a brand new 5V voltage regulator.

Before unsoldering the voltage regulator chip, make sure to know where precisely are each of its pins connected because you’d have to solder the new voltage regulator chip in the same way.

  1. Unsolder the damaged voltage regulator chip using a soldering iron and a sucker.
  2. Make sure you melt the solder completely and then suck it out.
  3. After removing the worn-out voltage regulator, all you need to do is solder the new one in its place.

You can find several tutorials to help you with soldering a new voltage regulator on your Arduino board.

Click here to check out a quick tutorial on how to replace the voltage regulator on an Arduino MEGA. You can use the same technique for other Arduino boards as well.

Is Your Arduino Turning On?

Once you know the cause why your Arduino I not turning on, is easy to move forward and fix it, you can solve this issue at home following whichever step described in this article applies to your case.

If you’re not able to solve it with any of the steps or find the real reason behind it, then you might consider buying a new Arduino board or consulting a technician to solve your problem.

I hope that this article has solved your Arduino problem.

Let me know in the comment section what other issues you’eve had with your board and how you solve it!


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

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