ST-LINK USB Communication Error

[Yunus Emre ERYILMAZ]

I have a STM32F411RE-DISCO board. At morning, suddenly it gave ST-LINK USB Communication Error. So, I updated firmware in ST-LINK Utility. After that, ST-LINK Utility and Keil gave same error. Also, I cannot connect via ST-LINK Utility right now. I updated both of them but nothing has changed. I changed 4 cables too. How can I solve it?

[Tesla DeLorean]

If it is just unable to take to the Target, try jumpering BOOT0 to VDD, and then reset and try to connect and erase the user firmware.

If you succeed, look at your code for things reconfiguring the debug pins, or putting the device in low power modes.

If all fails check the voltage on the target, and VCAP pins, in case you've blown something out.

[TDK]

Occasionally, mine gets into a state where it refuses to connect for 30-60 minutes, then starts working. Don't know the cause, but rebooting (or waiting) fixes it.