I using a board STM32l412 Nucleo 64 and I would like to use its ST-Link to load a firmware in other MCU (external application) , but the ST-Link does not connect to the other board. The hardware connection is ok.

[FDigi]

Is there some software configuration to do this procedure?

Thanks

[Uwe Bonnes]

How did you test the hardware connection if the ST-Link does not connect?

Did you try "connect under reset"

Is the target IO-Voltage 3.3 VolT? If less, Debugger will not recognize the level.

Can you test with another debugger?

Di you see signal on the connection with a scope?

[Tesla DeLorean]

You have a common ground?

Most often it is that the design you connect too is nonfunctional.

Check you have VDDA connected.

Check part orientation.

Check level on NRST.

Check voltages and capacitors on VCAP pin(s)​

[Mike_ST]

If not already done, you have to remove jumpers on CN2 and JP4.

It is recommended to update the ST-Link firmware as well.

[FDigi]

How did you test the hardware connection if the ST-Link does not connect?

I mean the wiring connection.

Did you try "connect under reset"

Not yet.

Is the target IO-Voltage 3.3 VolT?

Yes.

Can you test with another debugger?

I can connect with J-Link.

Di you see signal on the connection with a scope?

Not yet.

[FDigi]

Yes, jumpers removed.

[FDigi]

I can connect to design with J-Link.