9V battery block as VIN for STM32L432KC Nucleo-32

[ctron]

According to the manual UM1956 I can power my Nucleo-L432K board using 7-12V on VIN.

So I attached a 9V block to VIN and GND. It did not work, and all that happened was that I started to smell and got hot. It looks like the capacitor C25 was the component which got really hot.

The board worked before on USB. USB was not connected at that time. All solder bridges had been left to default.

As I am new to all of this, I do accept that it was probably my fault. However, I would like to understand what went wrong. What did I overlook.

[TDK]

Are you sure you connected it correctly? I don't see any reason why it wouldn't work.

C25 is on the output of the 5V regulator and shouldn't have an issue with this.

[ctron]

Thanks for looking into this, I really appreciate it.

I am confident, but not sure :) Thought I did it correctly, thus my quest to find out what went wrong, and seeking help here. I took some pictures, maybe that helps.

Here is the component which I suspect got blown, looks like C25:

Here is the overall setup:

And a check that the battery is ~9V:

 

Should be ok?!

[TDK]

Everything seems correctly hooked up as far as I can tell. Could be missing something. Definitely seems like C25 got fried. It's a polarized cap, so overvoltage or reverse voltage could fry it, but I don't see how that would happen with this setup. If I had a board I would test it for you.

[ctron]

So it looks like I didn't do any obvious mistake :)

If that makes any sense (and depending on what it would cost me) I could ship it to you.

[ctron]

I just wanted to follow up on this. I ordered a new board, used the exact same setup, and I did work right away, as expected.

 

Maybe it simply was a faulty board.

In any case, thanks for looking into this @TDK​!