Nano works then doesn't work

I purchased an Arduino educational kit with a Nano processor. For the longest time everything worked as it should and passed all sketch tests.

Then the Nano stopped working, not even running the blink sketch, with the Nano standing alone - not connected to any circuit. Nothing had changed, not the computer or Nano driver.

I purchased a new Nano processor from Arduino and the new board has never failed to work and run a sketch connected to the original PC and installed Nano driver.

The original Nano board sat for a long while, then I put USB power to it and it worked as it should for about a day, then failed again.

I know electronic components fail - my question for y'all: Why did the original Nano board fail, then work again for a short period of time before failing again.

Thanks for any help/advice you can offer.

And tell us what ELSE was connected to the NANO boards!
Paul

You are mistaken, electronic components are one of the most accurately produced products the world has ever seen. With modern testing failing components are rare.

However, because many structures are too small for you to see with your eye, modern electronic components can be damaged easily when used outside the datasheets specified conditions.

With programmable components the most likely cause of failure is your code. :slight_smile: Most example sketches assume a perfect world. For instance, some function return error codes that are often ignored. Have a look at your application and see where you may need to test some condition and add some error handling e.g., restarting a connection, filter noisy signals, ...
When this is all done, there are some techniques like the watchdog timer that allow you to reset the controller in cases that you did not anticipate.

have you got a link?

Klaus, that's presumpous of you to say I'm mistaken.

There are plenty reason why electronics can fail. Overloading in some way (see post #2 is aiming at that), ESD is another one.

Once you damage a chip, certain parts (e.g. protection diodes in the 328P) might initially be at the edge and hence it sometimes works and sometimes not. But eventually the chip (or pin) will completely die.

It could be a bad connection/soldering joint, for instance at the USB connector.
Mechanical stress can easily achieve that, micro USB connectors can be ripped off the board,
don't ask why I know that. :smiley:

I am sorry.

You do not have to believe me when I say failing components are rare. Check out the link below.

https://www.microchip.com/reliabilityreport/Default.aspx

Type in ATMEGA328P, pick one of the device names from the list and look at the data. The MTTF (mean time to failure) is several human lifetimes.

As others have confirmed electronic systems typically fail because of handling errors (ESD, mechanical stress) and using components outside their datasheet specification like overloading and software bugs.