ST-Link V2 won't connect after firmware update

[vs13]

After I updated ST-Link to firmware version V2J43S7 through STM32 Cube Programmer, I can't connect it to my laptop and program my STM32 F405 Feather board. I have attached the error message to this post.

[Tesla DeLorean]

Is this an Authentic ST-LINK? or boot-leg one?

If you break the PA13/PA14 pin operation you won't be able to connect. Reset with BOOT0=HIGH to stop running broken user code.

[vs13]

It is an authentic ST-LINK! I've reset the board, but I still can't connect. How would I break the PA13/14 operation?

[AScha.3]

>How would I break the PA13/14 operation?

If you set (in CubeMx ) not SWD debug, but use the pins for anything else ; then no more debug, as soon, as your program starts.

Then only can use bootloader, or hard reset (connect under reset, hard reset ( setting)) to connect.

[vs13]

I see! It doesn't look like I've done that, as I'm not using CubeMx and I haven't uploaded any program that uses either of those pins. Here's the code that I've previously uploaded to the board:

void setup() {
  Serial.begin(9600);
}

void loop() {
  Serial.println("Can read Serial!");
  delay(500);
}

[Techn · Accepted solution]

Try to connect while you press reset

[vs13]

Thank you so much, that fixed the problem for me!

[Tesla DeLorean]

The 10-pin SWD header should have a connection to NRST, allowing for a "Connect Under Reset" to actually be able to occur.

Connecting VCC, GND, SWDIO, SWCLK alone to the the ST-LINK will not.

I'm assuming you're using the SWDIO/SWCLK test-point pads on the F405 Feather

PA13/PA14 would get broken if you reconfigure the GPIO bank or pin settings to associate them with functionality other than debugger operation. Low Power modes can also break things as it removed power and clocks from the pin electronics.