My pcb did not work and i don't know why

I created my first pcb which is an arduino shield for the arduino mega.

I received the pcbs and i soldered all the components.

However, nothing on the board works. Not even the RESET button.

I have to note that the board has the same dimensions as the arduino.

However this isn’t the problem as i have placed insulation, and i keep the shield down, so that all the pins are inserted in the arduino…

Unfortunately i am not in a position to understand what is ti blame…

I have made errors like this one ( but i have removed all these capacitors.
And like i said, not even the reset button works.

I don’t know if other errors exist (this is my first board) and i dion’t even know how to debug the pcb.

I will upload the schematic and the pcb file here.

I understand that people have their own problems and maybe don’t have time for this.
I want to know that i am willing to pay someone who will look into this (paypal).

Thank you very much for your help!

a.kicad_pcb (414.1 KB) a.sch (29.5 KB)

EDIT: Here is the whole project (179.4 KB)

I have to note that it’s very weird that even the RESET does not work. Because RESET is as simple as pulling GND to a header pin.

holy hell that schematic is a war crime.

have you checked the operation of the button with a multimeter?


why do you have a separate power input not connected to the arduino 5V?

I think you can get the help you need if you are willing to put in the effort to provide more information.

  1. For the barrel connector power, is it set to positive or negative pin polarity?
  2. Can you upload the schematic symbol files that you used? U1, U2, and U3 are absolutely required to have any chance of knowing for certain where the problems are.

I would start with the basics:

  1. Verify the connectors are not reversed. i.e. are the connected to the correct part of your shield circuit?

  2. On an empty board (i.e. no components) apply 5V power and verify it goes where you think it should.

  3. On your schematic, it looks like your power and ground are connected just below the barrel jack (on your schematic)

Baby steps. Don’t try to troubleshoot everything at once. You could do it a number of ways but one way is to take a blank board, Add the connectors but no other components. Using a volt meter verify your connections are what you expect.

I’d like to say - you are very brave as you start your electronic adventure from something like that. I don’t know what arduino shield means. For me shield is a piece of metal closing the PCB inside it but it looks that here shield means something different.
I have started (many years ago) with simple external antenna + LC + diode + headphones to receive AM radio station.
Prepare yourself that at the beginning of electronic hobby most of the time you’re in a state of “why the hell isn’t that circuit working”. And the more such problems you solve yourself the more you learn.

The more problems will be solved for you by anyone else the less you will learn. If someone points you “here is the bug” and explains you why then it at once seems being so obvious that then you fast forgot it. If you spend hours searching a bug then when you at the end find it you will remember why it was wrong forever.
It is good for your mental health if you do not assume that shortly as soon as you design a circuit it will work well immediately.
Wish you everything good in your adventure with electronic.

It’s just a fancy marketing name for an add-on piggyback board you connect to your Arduino host.

1 Like

You can say that a shield is like a cape but for arduino …

…what is cape? think about it like a hat but for beaglebone …

you don’t know hat? it is like a wing but for the raspberry …

… i could continue this a couple of times more I believe :joy:

As explained by @fred4u all of them are expansion boards meant to be fitted on top of the board with the “brains” (microprocessor/microcontroller).


What is the exact BOM ? If reset is not working I suspect the pinouts of the switch do not align with the part you ordered

Also looking at the PCB file, its 4layers but the inner 2 are not used

No… I do not have a multimeter…

This is a mistake. Because the original analog circuit had a barrel jack, stupidly i sticked to that

Thank you…

  1. Hmmm i don’t know what you mean. The middle pin is Vcc and the other two external ones are GND
  2. What extension do these files have? I cannot seem to find them. But i found my custom symbol library files, they are {bck, dcm, lib} files. Are these the ones?

EDIT: I uploaded everything i have for this project in a zip file. Please look at the original question.
Thank you very much!

  1. Yes, for sure they are correct.
  2. I am not sure what exactly you mean with this…

Thank you for your kind words, but its a fun learning experience when you work for you hobby.
But if you are tight on deadlines and you just want to deliver your work and it does not work - at least the Hardware part, then it’s not fun.
The biggest problem is i dpn’t know what’s to blame, as everything looks good, and i don’t know how to debug this thing.

get a multimeter would be a good start…


Thank you…

Hmmm i don’t know what you mean. The middle pin is Vcc and the other two external ones are GND

Barrel jacks are available in center pin positive and center pin negative. If your barrel jack polarity was reversed it could cause problems. As @halachal reccomends, get a multimeter!

Never, and I mean NEVER start a (commercial, or payed) project with a tool that you are not familiar with.
Did you use a kind of autorouter?


You will have to get a multimeter. You do not need an expensive one as precision is not warranted here.

Amazon has meters from $10 and up. I would suggest something no lower than $20, only for the expected added reliability.


I think you might be looking at the whole board at once and find it overwhelming. As I suggested above, you start with simple things like is the power and ground connected the way you think it should (by your schematic. For instance; find the ground pin on your connector, then with the ohmmeter you will need to get measure from the connector to every component pad you have connected to ground. Then do the same with +V
Then make sure the +V is not connected to ground.
Move on to the reset and do the same.

You started with an advanced project. Which is fine but now you have to slow down and go in baby steps.