I finally got mine unbricked using "conventional" methods.
Here's the story:
1) Used ubuntu dfu-tool to load CLEAR_MEMORY_DFU.dfu . That left the NanoVNA white screened.
2) Tried to use dfu-tool to load a NanoVNA dfu. Couldn't: ubuntu no longer found NanoVNA, even in boot mode.
3) Installed DfuSe Demo on Windows.
4) Plugged NanoVNA into Windows box, in boot mode (2 pins shorted). Windows Search found and installed the STM driver (on the 3rd try). After that, Windows device manager always found the NanoVNA when in boot mode.
5) Used DfuSe to install the current NanoVNA dfu using Hugen's excellent instructions at . The important thing is that you are -upgrading-, not -uploading-. Use the Choose and Upgrade options on the right side of DfuSe.
Steve
