Unusual Flash Failure

[steph280]

I am having some weird issue with my Speedbee F405Wng. It was flashed successfully on an aircraft with dozens of flights. Recently it started complaining about barometric sensor discrepancy with GPS, preventing it from arming. So I tried re-flashing, only to have it fail halfway.

Now subsequent flashing attempts would finish, but at the verification stage it would end with “Programming: Failed.” Then the FC would not reboot after going out of DFU mode.

It’s not driver issue or any usual suspect, as I am able to get into DFU mode and start/finish the flashing process. But I did try reloading STM CP210x and WinUSB drivers (stand alone install and also through Zadig), different PC, different cable, different software (inav, betaflight, ardupilot), and I also tried flashing with STM32 Cube Programming application.

And I did try to disconnect GPS/RX/VTX/etc. Pulled out the microSD card as well. Right now it has nothing connected to it except USB to PC.

I know you can’t brick a STM32 FC like these, so this has me really stumped.

Any recommendation is greatly appreciated.

[sensei-hacker]

Have you been flashing with full erase?
That might be worth trying if not.

Otherwise, accidentally having the wrong target selected can create similar issues, or there is damage to the chip.

[steph280]

Yes Full erase and with/without boot sequence.

If wrong target was selected, it should restore when correct target is re-selected right? How would I fix this otherwise?

Thanks for the response.

[error414]

yes, does not matter you flashed (or tried to flash) wronf target, just flash correct one.