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Topic: Arduino mega 2560 heating up (Read 845 times) previous topic - next topic

Hi all,

My arduino mega 2560 was working fine until after a new configuration for software, the regulator on the board became really hot. (gets hot to the touch after 4-5 seconds). This board is mounted onto a PCB and before this installation of new codes the regulator didn't heat up this much. running an old code, the regulator still heats up. Could a possible short circuit somewhere cause this temperature? If so what would be a likely place that's been shorted for this to occur?

Thanks.

hiduino

How is it mounted?  Are you using any kind of standoffs between the mega board and pcb?  If not you may be shorting something the bottom of the mega board.


The arduino is mounted upside down on the PCB, nothing on the bottom side of the pcb looks shorted.
What's even more weird, when we hook up the amp meter to see if anything is shorted, the current seems to be correct, but the arduino is not heating up anymore. But without the amp meter, the arduino regulator starts heating up.
The same thing happens if we use a dc power source on our test bench, using this source the arduino does not heat up no matter how much current we're drawing, but if we use batteries then the arduino starts to get very hot to the touch.

Is your Arduino a standard unit with a standard linear reg or do you have a Freetronics which has a more effective switch mode reg?

You have a multimeter right?
Questions;
How are you powering the Arduino, with external power supply, or are you using USB power from your computer?
First check,
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Unplug your power supply and check the voltage of your power supply going into the Arduino, unplugged.
If you use an external supply, it needs to be within spec. Max is typically 24 vdc.
If you are using usb cable, it too needs to be within spec, and this is 5 volts dc.


If the above checks out proceed to next step below,
Remove any I/O devices you have connected to your board, that is, remove all wires.
Plug your power supply cable into your Arduino,

If using external supply
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check the voltage of the Vin pin, it should be the same reading as you read before.
Next, check the output voltage of your onboard regulator, you should read 5 volts all being well.
If it is significantly greater than 5 volts dc, remove power supply and replace regulator.
If voltage is 5 volts dc, and board is cool, and you removed some wires for I/O, then suspect your I/O or the way you are using your I/O ports, check software.
Try loading a simple blink program, dos it still get hot?



If you are using USB power,
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You potentially have an issue with the electronics on the Arduino.



Paul

hiduino


The same thing happens if we use a dc power source on our test bench, using this source the arduino does not heat up no matter how much current we're drawing, but if we use batteries then the arduino starts to get very hot to the touch.


Question, what voltage is your bench power supply?  What voltage is your battery supply?  Depending on your input voltage that could cause the regulator to over work.  The higher the input voltage above 7v the hotter it may get, due to the power dissipation it need to do to convert it down to 5v.  So that heating may be normal result of too much input voltage.  You may need to try a lower input voltage, but don't go below 7v or the regulator may not put out 5v properly.


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