During testing, Suddenly HOST PC stop detecting the board saying unknown device. NO VID/PID was recorded also. So, we need to upgrade the firmware again But the ST-Link USB is not working only. Is there any other way to upgrade it. Kindly suggest
Replug the device. This should bring up the bootloader. If not, you have trashed the stlink somehow. If the bootloder comes up, download stswlink-0007 and run "java -jar STLinkUpgrade.jar" in the appropriate directory.
