Hello, I have a short circuit between the RESET and the VCC. I measure a impedance of 1ohm between these two signals and 80ohm with the GND. The RESET pin only goes on a 0.1UF capacitor and on the programming connector.

[ludovic-micou2]

the ST-LINK can't detect the micro but the software who is already programmed in the micro work perfectly.

Does anyone have an explanation why the reset breaks like this?

[TDK]

If NRST is shorted to VCC, there's a hardware error or you've damaged the chip. There's no setting you can enable that would do this.

Likewise, if VCC has 80 Ohm impedance to ground, that also indicates a likely hardware error.

Also possible you're measuring it incorrectly, such as with the debugger attached or with it powered.

[lmico.1]

The measurement was made with the power and probe cables disconnected from the board. The measurement