My original ST-LINK/V2 has been broken. There was the Short circuit between VDD and GND pins. I changed the MCU(STM32F103C8T6) and the voltage regulator(LD3985M33R) with new ones. Short Circuit problem gone, but when I plugged ST-LINK to USB port, the indicator LED is on very lightly. USB Device not recognized window shown at PC screen.
I measured VDD pin as 3.29V. Power is OK.
ST-LINK/V2 is not open source and I couldnt reach its schematic.
What should I do to fix the issue? Thanks your helps…
Best Answer
You need to upload ST Link firmware onto the MCU. It might be possible with some soldering/desoldering involved.
I am not sure if the original firmware is available freely, but there is STSW-LINK007 firmware update package on ST site and I suspect it contains entire firmware ready to upload.
The first problem is that the MCU must be in DFU mode for this. It is done by selecting system memory boot mode (boot0 = 1, boot1 = 0). So, you have to find a way to temporarily connect boot0 pin to VCC and then power reset. Preferably without making another short on board.
The second problem is that STSW-LINK007 requires USB DFU bootloader, and there is a chance the one installed on your MCU uses UART protocol. See AN2606 for details. If this is the case you'd have to connect USB-Serial adapter board to UART port pins and install USB bootloader first, then try firmware update again.
But frankly, I agree with the comments left on your question - unless you are doing this for fun and education, it is not worth the time spent.
Finally, it might be a bad photo angle, but it seems you have a lot of bridging on the MCU chip. You might want to check that out first.