STLink on STM32F4 discovery board does not work.

[PSand.5]

The built in STLink on STM32f4 board is not working. I have used this board for several months and suddenly the STLink is not working.

ST32F4 discovery board - MB997 D 01

In windows when I connect the board, it shows the error 43 (device descriptor failed). And in the ST Link the LD1 blinks red. The STLink does not get identified by STLink utility.

[Tesla DeLorean]

Is is possible you shorted out or damaged the board in some way?

Same cable as before?

Perhaps using a multimeter or scope probe a couple of the supply/power rails, per schematic.

[PSand.5]

I used the same cable as before. I do not think I damaged the board hardware. I checked using the multimeter and it seems okay with power supply. What my guess is there is a software issue with the STLink MCU

[Tesla DeLorean]

Not sure how that would have sustained bit rot. Did you update the firmware on it and did that fail?

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I​f code running on the F4 is the problem, strap BOOT0 to VDD, and if you can connect then, erase the code that's on the F4