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First, nearly every 'white screen" topic here I've looked at seems to be related to firmware upgrades. I have tried to find a solution before asking about this. I was using the Nano to check resonances at various lengths of a 17' whip antenna. After a few readings, I came back from the antenna to find the screen locked with a partial display that would not respond to touch. I turned off the Nano and now all I get is a white screen. I plugged it in to the USB and Device Manager doesn't see it. There has been no damage and very little prior use. Is a firmware upgrade the next step, or do I need to do anything else first? Everything on the board looks intact.
Thanks in advance,
Perry
KG4KTB

You left the NanoVNA and went to the antenna. Did you touch the antenna element? If so you may have had an ESD event. Or did you use a transmitter at any time? This might have damaged the front end.

Roger.

Yes, I adjusted the whip. No transmitter use. Can it be fixed?
Perry

On Thu, May 26, 2022 at 6:39 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

You left the NanoVNA and went to the antenna. Did you touch the antenna
element? If so you may have had an ESD event. Or did you use a
transmitter at any time? This might have damaged the front end.

Roger.

On Fri, May 27, 2022 at 04:15 AM, Perry Westberry wrote:

Yes, I adjusted the whip. No transmitter use. Can it be fixed?
Perry

One thing you might try is to charge the unit overnight. Then open the case and then disconnect the battery by taking the connector off the board. Wait a minute or so and then re-connect the battery. This may help if the CPU chip is in some unknown state....

Roger

Thanks, Roger. I'll give that a try.
Perry

On Sat, May 28, 2022 at 1:40 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Fri, May 27, 2022 at 04:15 AM, Perry Westberry wrote:

Yes, I adjusted the whip. No transmitter use. Can it be fixed?
Perry

One thing you might try is to charge the unit overnight. Then open the
case and then disconnect the battery by taking the connector off the
board. Wait a minute or so and then re-connect the battery. This may
help if the CPU chip is in some unknown state....

Roger

Yes, disconnect all power for a while. The ultimate and first try to fix ANY and EVERY computer that I know of. Even my wife has learned that.

Dave K8WPE

David J. Wilcox’s iPad

Tried this and still just a white screen. I guess it's bricked. Thanks for all the responses.
Perry

On Tue, May 31, 2022 at 06:44 AM, Perry Westberry wrote:

Tried this and still just a white screen. I guess it's bricked. Thanks for all
the responses.
Perry

You posted that you cannot see it in Device Manager. Can you see it in DFU mode? This will require opening it and shortening 2 pins.

Roger

Hello,
Being a past bata tester of FW for this unit, I have dealt with your problem.
The way I cured it is as follows:
First shut down the NanoVNA.
Remove the back cover.
Using small tweezers or what you ha e short the boot pad to the vcc pad next to it. While keeping the short, turn on the NanoVNA.
Remove the short, shut the NanoVNA off. Replace the back cover.
Now turn the unit on.
You should be able to re install the new, or old, FW by putting your NanoVNA in DFU mode via the menu,
I have had to do this several times so, I installed a micro switch to short the two pins without having to take the unit apart.
Clyde KC7BJE

Then turn the

Roger,
It now shows in Device Manager. The screen is still while but I can connect
with Nanovna Saver and calibrate using the Calibration Assistant. Do you
think it's usable when connected to the computer to analyze an antenna? I
may need to use it with NanoVNA App on my laptop. NanoVNA Saver won't
install on the laptop due to a Windows dll error.
Perry

On Tue, May 31, 2022 at 4:04 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Tue, May 31, 2022 at 06:44 AM, Perry Westberry wrote:

Tried this and still just a white screen. I guess it's bricked. Thanks

for all

the responses.
Perry

You posted that you cannot see it in Device Manager. Can you see it in
DFU mode? This will require opening it and shortening 2 pins.

Roger

A few days ago, I was able to get the unit into DFU mode and it was
recognized in Device Manager. I installed the latest Firmware and was still
getting a white screen. At the suggestion of another post, I left the
analyzer off for a few days with the battery disconnected. I powered it
back up today with the results that it now shows in Device Manager and I
was just able to run a calibration through NanoVNA Saver but the screen is
still white.
Perry

On Tue, May 31, 2022 at 4:24 PM Clyde Lambert <clyde.lambert@...>
wrote:

Hello,
Being a past bata tester of FW for this unit, I have dealt with your
problem.
The way I cured it is as follows:
First shut down the NanoVNA.
Remove the back cover.
Using small tweezers or what you ha e short the boot pad to the vcc pad
next to it. While keeping the short, turn on the NanoVNA.
Remove the short, shut the NanoVNA off. Replace the back cover.
Now turn the unit on.
You should be able to re install the new, or old, FW by putting your
NanoVNA in DFU mode via the menu,
I have had to do this several times so, I installed a micro switch to
short the two pins without having to take the unit apart.
Clyde KC7BJE

Then turn the

On Tue, May 31, 2022 at 02:11 PM, Perry Westberry wrote:

A few days ago, I was able to get the unit into DFU mode and it was
recognized in Device Manager. I installed the latest Firmware and was still
getting a white screen. At the suggestion of another post, I left the
analyzer off for a few days with the battery disconnected. I powered it
back up today with the results that it now shows in Device Manager and I
was just able to run a calibration through NanoVNA Saver but the screen is
still white.

This sounds like you may have a defective screen issue. I recall others had this problem and opened up the unit and checked the solder connections. Some cured it by gently re-soldering connections.

If you are going to use it as is with a PC program use NanoVNA App. It will use raw uncalibrated data during calibration while Saver depends on a calibrated NanoVNA. NanoVNA app also does firmware flashing. If you are new to nanoVNA app see my previous post on it >>> /g/nanovna-users/topic/91143866#28096

Roger

Thanks for the link, Roger. I'm going to try using it with NanoVNA App. If
I feel adventurous, I may try fixing the screen. Thanks for your help.
Perry

On Tue, May 31, 2022 at 5:42 PM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:

On Tue, May 31, 2022 at 02:11 PM, Perry Westberry wrote:

A few days ago, I was able to get the unit into DFU mode and it was
recognized in Device Manager. I installed the latest Firmware and was

still

getting a white screen. At the suggestion of another post, I left the
analyzer off for a few days with the battery disconnected. I powered it
back up today with the results that it now shows in Device Manager and I
was just able to run a calibration through NanoVNA Saver but the screen

is

still white.

This sounds like you may have a defective screen issue. I recall others
had this problem and opened up the unit and checked the solder
connections. Some cured it by gently re-soldering connections.

If you are going to use it as is with a PC program use NanoVNA App. It
will use raw uncalibrated data during calibration while Saver depends on a
calibrated NanoVNA. NanoVNA app also does firmware flashing. If you are
new to nanoVNA app see my previous post on it >>>
/g/nanovna-users/topic/91143866#28096

Roger

Et voilà Roger, thanks to you !!

73's jean Marie F5VLB