Hi

Where can I find the Nanovna v2 plus 4 main board schematic?

Thanks

Clones and proprietary are the only two words that come to mind when this question is asked...
Then again there is reverse engineering but good luck with that!

I doubt that the designers would release thatthey already have enuf
problems with people creating clones

cheers
Dave

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Mon, 26 Feb 2024 14:36:06 -0800
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[nanovnav2] Nanovna v2 plus 4 main board schematic

Hi 

Where can I find the Nanovna v2 plus 4 main board schematic?

Thanks 


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Someone posted the for a USB C charging problem


A real usb-c charger needs a 5.1kohm pull-down resistor to start providing 5v VBUS https://electronics.stackexchange.com/a/314188/172286

These resistors have been added between version 3.1 and 3.3.

3.0 schematics https://github.com/hugen79/NanoVNA-H/blob/0fea2293aaf15a76923ec121635489e6c9526613/doc/Schematic_nanovna_Sheet-1_20190711140429.jpg
3.3 schematics https://github.com/hugen79/NanoVNA-H/blob/bf6e64393a983fad2cf1f8a339cdd19b1fbac433/doc/Schematic_nanovna-H_Sheet-1_2019092.png

There is a link to the github repository on their website
https://nanorfe.com/nanovna-v2.html#schematics
The schematic software used appears to be gEDA (which I gave up trying to install on Linux because it seems to be an old program with a lot of dependancies on old stuff yada yada) but they also have a PNG image of the schematic in github which matches the V2 Plus4 board I have. I wish they would migrate the project to Kicad.

Hi, you can find schematics for the V2_2 version on our website at nanorfe.com. We do not have public schematics for newer hardware versions like the V2 Plus4.

Thanks for answering my question.

My problem is that the U861 burned and the board is destroyed.
I was able to get an MXD8641 to replace it, but I need to rebuild the connections on the board.

The truth is that I don't know if I'll be able to do it but I have to try.

Could you share the details of the connections with me?
Do you have any advice for repair?

Please see attached a photo of the board.

Thanks in advance
Greetings,
Arturo

Is it the can traces that got screwed up , or the IC wires>

The easy way is to clean the pads with solder wick (add flux) and flux
remover. Then put a tiny bit of low temperature solder paste (bismuth -
tin) on the pads (e.g. with a tooth pick) and use a heat gun to reflow
it. No worries about shorts if you use just a little bit of paste. It
also has good self aligning properties. You'll need much more heat when
using lead-tin or (almost) pure tin solder paste.
If you don't have solder paste, just make sure there is a tiny little
bit of solder on each pad and add a few drop of flux. Then reflow with
the heat gun.
There are a ton of youtube videos how to replace smd parts. I've
succesfully revived 4 units. And add an ultra low capacitance esd diode
at the input to protect the switch. (Search the forum, I've posted the
part number several times).

Succes, Reinier

Op 29-2-2024 om 16:40 schreef Arturo LU6ETB:

> Thanks for answering my question.
>
> My problem is that the U861 burned and the board is destroyed.
> I was able to get an MXD8641 to replace it, but I need to rebuild the
> connections on the board.
> The truth is that I don't know if I'll be able to do it but I have to try.
> Could you share the details of the connections with me?
> Do you have any advice for repair?
> Please see attached a photo of the board.
>
> Thanks in advance
> Greetings,
> Arturo
>

The mxd681 caught fire and the prints were ruined.
I hope it's just the IC connection traces.
My idea is to clean the board well, glue the IC and solder the legs of the IC.
In order to do this, I need to know where to connect the pins of the IC.
That's why I was looking for the motherboard diagram.

If the diagram is not available, I would appreciate at least the connections of IC U861

Greetings,
Arturo

Hi Arturo

See the attached pic of my Nano VNA V2 Plus4 board. As far as I can tell, the U801 chip is wired the same as in the V2_2 png schematic.

Good luck - although I suspect other damage was done to your board too.

Cheers

Andrew

Hi Andrew,
Thanks a lot for the picture.
Greetings
Arturo

Hi,

I have the main board picture (Thanks Andrew) and the MXD8641 IC.
Now, the issue is how to solder it and reconstruct the traces. I found the MXD8641 is a QFN-14L 2mm×2mm×0.55mm package.
Then, I think I will not be able to do the repair.

On one side
I reached Tindie store and they said that they don't sale spare parts and suggested to contact factory.
Feb 23rd, I sent and email info AT nanorfe.com, CC edelswartz123 at gmail.com requesting the spare and there was no answer.

On the other side
I found an adapter at https://www.proto-advantage.com/store/product_info.php?products_id=3100127

What do you think about this adapter?
Has anyone tried it?

Thanks & Regards,
Arturo