Built-in LED flashes when NANO stops working

[TomGeorge]

Hi,
Did you make a PCB for your project?

Can you post some images of your project?
So we can see your component layout.

What is the power supply?
Have you monitored the power supply before and during the fault?
(Troubleshooting 101)

Thanks.. Tom..

[sparkie7819]

I removed all code referencing the IRRemote and uploaded it to the NANO and the clock worked flawlessly for a couple of hours, where it wouldn't run more than a half hour before. So, then I put all the code for the IRRemote back in and uploaded it, and the clock has worked perfectly all weekend. I didn't make any hardware changes or changed the code in any way. The only thing I can think of is some kind of glitch happened when I originally uploaded the code. I just know if I ever run across a weird problem like this again, one of the first things I'll do is reupload the program. I want to give my sincere thanks to everybody who tried to help me with this.

[TomGeorge]

@sparkie7819

The segment LEDs are actually a 3 LED strip cut from a 12 volt LED strip light, which has a built-in resistor, which is why you don't see LED resistors on the drawing. According to my meter, each 3 LED strip draws 0.046 amps. It is powered by a 700mA 12VDC plug in adapter.

How many digits is your clock?
Have you actually measure the current?

Thanks.. Tom...

[sparkie7819]

TomGeorge: To answer a couple of your questions - it is powered by a 12VDC plug in adapter. And, yes, I did measure the output voltage and it was the same before and after the fault. It is a 4 digit display. The only voltage discrepancy I found was at Pin 1 (data in) of the MAX7219. Before the fault I read 2.xx volts, and after the fault I was reading less than 1/2 volt, which I took to mean the Arduino was no longer sending out a data signal. But the clock is now working. I removed all code referencing the IRRemote and uploaded it to the NANO and the clock worked flawlessly for a couple of hours, where it wouldn't run more than a half hour before. So, then I put all the code for the IRRemote back in and uploaded it, and the clock has worked perfectly all weekend. I didn't make any hardware changes or change the code in any way. The only thing I can think of is some kind of glitch happened when I originally uploaded the code. I don't know what else it could be. I do appreciate all the help you and everybody else has given me.