Yes, this is about a clone unit - but one that is supposed to be one of the working ones. I have not been able to update the software even using NanoVNA QT or by trying to use dfu mode on its own. While trying all these steps, I have a new problem: while moving the usb plug from one laptop to another (Win 10 to Mac iOS 10.13.8) to try using the QT app, the screen went completely white. Now when I turn it on, the white screen comes on, whether plugged in on usb or sitting there by itself. When it is plugged in, the charging program seems to be working, since the 4th light kept flashing and then went solid red.  I tried tapping the screen and moving the three buttons, each one in all different directions while turning the unit on - no joy.
Here is the data I copied off the config page before the screen died:
NanoVNA SAA-2N (N connectors)

Version: git-20200617-1a9a11
And on the back serial # N20101229 .
As I did before, I opened the unit again to see if the screen plug was loose. It was n't and the screen did not start up again.
Thanks for any help you can provide.

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72/73 de K1QED  bob.c
Robert J. Coleman

Try using Microsoft's utility program "USBview" which will show all usb ports and indicate which ones are active.  Perhaps your usb interface is in a coma.
This has happened to me twice and I do not know the solution.  I was seduced by the low prices and they shipped me an unreliable product.

Hi John, well, this was odd!   I tried a suggestion from Tim Dawson on the N-Savers group: hook it up to the laptop on the -QT softwre, aan try going into dfu mode using the buttons, not the screen. Up pops the screen, alive! But then moving the usb plug very slightly, I lost the connection - the cable seems to be the problem. So while I was following the steps on the -QT page, I was able to get to the download page and  got the latest software dtd 4/3/22. The firmware id# does not show up on the Version screen, however, and I'm not sure which of the many downloads I grabbed.
Thanks for the usb connection suggestion, now I gotta find out exactly what I got for software...not sure I got the right one for this SAA-2N.
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72/73 de K1QED  bob.c
Robert J. Coleman

Update - got the incorrect F/W offloaded and the correct one on, now to try calibration. Thanks to all who messaged me directly and in here; and also to all those in the past messages who provided the resolution to my errors. One comment on the new F/W dated April 2022: it did load but did not work on my SAA-2N, but it had a bunch of new capabilities for the newer vna's. I'm tempted to make the jump to a new device, but I plan to wear out this one first!
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72/73 de K1QED  bob.c
Robert J. Coleman

Hello Robert!
What is name of downloaded FW file from April 22? Is it FW for V2Plus4? It is false. Not for SAA-2N.

Last official FW from developer team for V2 hw version 2.2 was 20201013. Nanorfe team support this hw not more!

I send You last  FW file from DiSlord. Please easy  rename this file from .bin.txt to .bin extention.
Any menue points are for sd card not in use (mod required). After upgrade touch screen calibration as first.

I send You V2_S-A-A-2_Structure Map for saa-2/saa-2n from Dieter DK2AM. Dieter has modified his SAA-2N - battery voltage control, micro sd slot. This Structure Map for FW Version 1.3.00.

73 de Vladimir, dl7pga

The one I sent you did not work? In what way?

https://cloud.hamoperator.org/s/9aQejsS2Fs8erCk

Danny

> From: "Robert Coleman" <rcoleman@mass.rr.com>
> To: NanoVNAV2@groups.io
> Sent: Saturday, June 11, 2022 2:58:34 PM
> Subject: Re: [nanovnav2] White screen on NanoVNA SAA 2N #clones

> Update - got the incorrect F/W offloaded and the correct one on, now to try
> calibration. Thanks to all who messaged me directly and in here; and also to
> all those in the past messages who provided the resolution to my errors. One
> comment on the new F/W dated April 2022: it did load but did not work on my
> SAA-2N, but it had a bunch of new capabilities for the newer vna's. I'm tempted
> to make the jump to a new device, but I plan to wear out this one first!
> --
> 72/73 de K1QED bob.c
> Robert J. Coleman
>