instant Hot(and possibly dead) Arduino nano on 12v

Hello community, It’s the second time i get this problem with my project.

I made this sound reactive LED strip that i power with the 12v adapter that came with the strip. the projet last months and were use without any problem in multiple party when suddenly I pluged it and the LED strip became only white (don’t change with the music anymore) and the microchip on the board became instant burning hot (i burned my figers twice).

at the time i change the arduino and the mic an it started to work again for another years.

But this time i made a new revision of the PCB and i used the same arduino that last a years an did not died yet and the problem has appen again yesterday when i tried my new PCB!

is my PCB the problem ? why is this projet always end up burning hot and possibly die some years later ??

I have attached my last PCB schematic and the .ino file.
this is my pcb project
https://www.pcbway.com/project/shareproject/Music_sound_React_RGB_LED_STRIP_5050.html

let me know what you think!
Thank you!

RGB_SoundReactTEST.ino (4.67 KB)

There's nothing obviously bad on that schematic. 12V power goes to the Nano and the LEDs and it doesn't look like you're drawing a lot of power from the 5V pin on the Nano. What does that power do though? Microphones? I don't know what mic might use 5V.

"Enter model name here" is an unusual transistor type. Do you have a datasheet for it?

Thanks Morgan for your answer,
first those are not transistors but MOSFET IRFZ44.
and for the microphone, my pcb is design to support 3 microphone board available on Ebay(but one at time and the code need to be change). but The one i currently use is MAX9814 from ebay ("Supply Voltage: 2.7v-5.5v @ 3mA current" according to amazon)

Electret condenser mic's require DC power source.

this is for Morgan who wanted to know what mics need 5V

wolframore:
Electret condenser mic's require DC power source.

I don't thing that's the problem here because it worked fine for months and and is'nt the arduino 5v a DC voltage already ?

Always best to show your wiring too.

BTW, those are transistors. :wink:

There are BJTs and there are MOSFETs.

Suggest you you use a MOSFET that is designed for logic level switching.

A series gate resistor of ~220 Ω is highly recommended.

Please confirm your power supply is 12VDC regulated.

larryd:
Always best to show your wiring too.

I'd love too but my wiring is my PCB, nothing more to show there.
It should be the exact schematic as shown in the picture.

larryd:
BTW, those are transistors. :wink:

There are BJTs and there are MOSFETs.

Thank you for the info :slight_smile:

Please confirm your power supply is 12VDC regulated.

At least we can see the wires going to and from the PCB.

It's a dead-simple schematic and the choice of transistors won't burn up the Nano instantly. (The "T" in "MOSFET" means Transistor.)

I suspect some other wiring fault, such as a 3V wire to a mic getting shorted to ground somewhere.

I'm not home at this time to take picture of it but there's a picture from ebay of what i think is the same power supply i used and come with the LED Strip.
i use the 12v straight for it without any regulation


maybe i'll post later a picture of my board assembled

Yes it's a simple shematics and I can't wait to try it with a new arduino nano to see if i will work with the same PCB and same microphone board.

As i said, i 'dont think it was an instant dead for my nano, i'm suspecting that cheap arduino ripoff from ebay are simply not that durable ? maybe this one got damaged will i was soldering the pcb... what you think ?

for you info, I tried after to plug directly the 12v supply to my arduino nano Vin and again the atmega chip onboard burned my finger instantly.

I once got some Pro Minis from China where the silk screen labels were wrong :frowning:

Are these real official nanos? I ask because the bought some I got as a 5 pack off amazon (not genuine) and the regulator on them was terrible and they all burned up if you used them at 12v...

No, those i baught are definitely not genuine Arduino nano :grinning: .

but they got the job done for me for dozen of my projects.

maybe as you say the regulator is garbage and that why it keep died on this project after couples of months.

Those tiny regulator packages can only dissipate so much heat. If asked to to more than power the Nano and maybe a few LED's while dropping from 12V there's a lot of heat generated. Plus the regulators are underneath the NANO and soldered in place it's trapping heat. They create about 40C per watt... so if you run them over a few hundred mA and on 12V they won't last long... even with a Genuine Arduino Nano.

How about: the regulator eventually fails short, and passes 12V directly to the 328's Vcc pin.

ShermanP:
How about: the regulator eventually fails short, and passes 12V directly to the 328's Vcc pin.

ShermanP, maybe your right, i should test the conductivity between vin and 5v to see if it is shorted.

wolframore:
the regulators are underneath the NANO and soldered in place it's trapping heat.

In my case the arduino is not directly solder to the board, it is connected with female and male header in case my arduino need to be change (which it need to be after all..) so the heat is not trapped

wolframore:
if you run them over a few hundred mA and on 12V they won't last long... even with a Genuine Arduino Nano.

I run my arduino on 12V but i only use 3mA according to Amazon with the mic that use 5V.

Other UPDATE: I confirm that my nano is dead because the arduino IDE does not see it anymore. Also, i found out my PCB had a mistake because the 3 mic slot output share the same D5 pin, but to use the MAX9814 Mic it should be connected to an analogue pin. Just so you dont over analyse my shematics and tell me this.
I hardly think that was what cause the dead though.

Also the code i give in my first post does not match the pin used for the pcb just so you know.

OMG i burn another one but i find out why it burned this time.
It was the 3 pos switch that have a wierd circuit diagram so i was shorting the arduino with 12v every time..

Thanks for the feedback. Good to know you finally found it.

It pays to read datasheets carefully doesn't it?

Yes it does but for my défence the datasheet was not that easy to find so i did not Bother.. i learned