NO STM 32 Target Found, Target No Device Found (Nucleo-F446RE)

[cherrytasty]

what should i do..?

[SofLit]

Hello,

First check if you are using a data cable not a charging cable

[Tesla DeLorean]

Do you have code that's reconfiguring the PA13 / PA14 debug pins, or putting them in a low power or sleep state?

Do you observe this problem if you pull/set BOOT0 pin HIGH? Here your code on the device won't be running and potentially breaking things.

[Andrew Neil]

https://community.st.com/t5/stm32-mcus/how-to-solve-debugger-connection-issues/ta-p/49693

[TDK]

> Target voltage: 0.31 V

This is a power issue. No change of a chip working without a proper power supply. Ensure the power jumper is set correctly. Perhaps a part on the board got damage in the course of debugging. It sees the ST-Link chip, so the board is probably okay. Consider looking at the schematic to track down the power issue.