My Arduino Nano decided to stop working?

Hello,

So I have this little 8x8 led matrix game powered by an arduino Nano here:

The little thing was working just fine and dandy for quite some time until a couple of days ago the whole USB computer interface stopped working entirely. I was just in the middle of using it hooked up to my computer when it just stopped powering on. I unplugged it and replugged it in a few times to see if I could get it to work with no luck.

If I power it on by using a 9v battery (like in the next picture) it is able to function. The led on the arduino lights up and the LED matrix lights up.

now, it should do the exact same thing when I plug it into my computer by USB. However, when I do that now nothing happens at all. The led doesn't light up and my computer doesn't even seem to recognize it:

But it definitely isn't the computer or the cable's fault, because I have an identical Nano that when plugged into the same computer with the same cable it powers up fine:

This would lead me to believe that it is probably a hardware issue on the arduino, but I checked out the physical plug and compared to my spare arduino nano. The connector looks to be identical and doesn't look damaged in any way.

So this means that it isn't the being caused by a fault in the actual circuit, it isn't the computer's/cable's fault, it isn't the plug's fault, but what could it be?

Thanks in advance to anybody who has any advice!

I can't help you but I had the same problem with an Uno. It's running a useless-unfinished program and I can't re-program it. I don't know if the problem is the boot-loader, serial ports, or USB chip.

I bought an AVR ISP programmer (about the same price as replacing the Arduino) to re-porgram it, but that didn't work either. I think that's a different problem because the error message seemed to say that programmer wasn't recognized by the Arduion IDE. (I never tried the programmer with a known-good Arduino.)

So now I just the bricked Uno as a template if I need to drill mounting holes in a box/chassis, or if I want to look at the pinout locations, etc. :smiley:

Is there 5V present when it's plugged into the USB?

Look on the attached schematic, bottom of the page, in the middle; D1, "5V Auto Selector". It's VUSB on one end, the other (the 'output') goes to "+5V"

ArduinoNano30Schematic.pdf (200 KB)

You might have broken something on the Arduino itself, you should try probing the Arduino with a multimeter to see if there's any voltage present on the actual board.

There is a diode between Vusb and 5V.

I don't know what that IC does, but if it doesn't limit the current to those LEDs (I'm betting on, it doesn't) then you may have drawn enough current to damage that diode.

While connected to USB, I would measure the voltage across both sides of the diode.

DVDdoug:

I'm not really sure what you're trying to say... I see the portion of the schematic your referring to but what am I supposed to do with this? Sorry...

ebird97:

well the main portion of the arduino must still be functional if it can still run when powered by the 9v battery, so what exactly would I be looking for when probing?

Shouldn't the resistors I have drop the current enough to prevent that kind of damage? I don't know if you can see them but there are 8 of them (one for each row on the screen) right up against the nano.

Oh and the IC is just a shift register.

Jumbosize:
Shouldn't the resistors I have drop the current enough to prevent that kind of damage?

No, I didn't see the resistors. my bad.

I'd still check to see if the diode is damaged, that's the gate between the regulator/5V pin and Vusb.

Okay, I will. However, do you know where it might be located? because if it is on the underside I have no way to get to it since my nano is directly soldered in place.

Jumbosize:
Okay, I will. However, do you know where it might be located? because if it is on the underside I have no way to get to it since my nano is directly soldered in place.

As I recall, it's on the bottom. next to the tantalum caps (yellow parts).

Am I here?
Like I said in Reply #2:
Look to see if there is 5V at the 5V pin when it's plugged in to the USB connector.
If there's not then that diode is shot.

Yes I saw your first post Runaway Pancake and I guess you didn't see my response where I said I wasn't sure what you were asking...

Can you please explain what you mean? I'm sorry, I guess I don't know enough about this to know what you're telling me to do. Do you mean with like a multimeter or something?

Plug your Nano into the USB
Get out your voltmeter.
If you don't measure 5V with the positive lead on "5V" and the negative lead on one of the Nano's "Gnd" terminals then that aforementioned diode is b-a-d.

Okay thank you. I will check that right when I get home and I'll tell you the results

OK

Jumbosize:
Yes I saw your first post Runaway Pancake and I guess you didn't see my response where I said I wasn't sure what you were asking...

Well, given --

Jumbosize:
DVDdoug:
I'm not really sure what you're trying to say... I see the portion of the schematic your referring to but what am I supposed to do with this? Sorry...

I'm not DVDdoug, so I jumped right over that.

My apologies, I meant to put your name.

Well I am now home but I can't seem to find my multimeter anywhere... I guess we'll have to put this endeavor on hold until I find it. Unless somebody else has advice.

I'd like to thank everybody who has given me feedback so far, I really appreciate it!

Alright, so I found my multimeter and tested as suggested. There did not appear to be 5V present so I suppose the diode is indeed shot.

Now I guess my question is what could have caused that to happen? It literally just happened out of nowhere while it was plugged into my computer.

Diode failure -- Too much current through the diode, as exceeding the PIV was more unlikely.
Easy enough to replace.

You'd have to post a complete schematic of your project for someone to be able to point out a specific (likely) cause.

It happened to me too.
I was just testing an lcd 16x2 hooked on a I2C bus to the nano.
Could the lcd backligth fried the diode ?

0VV0:
It happened to me too.
I was just testing an lcd 16x2 hooked on a I2C bus to the nano.

Could the lcd backligth fried the diode ?

Yes, very much so!

// Per.