The USB VBUS doesn't work. It is not recognized.

[MAlon.2]

I've been programming with a STM32F407G, but the USB VBUS doesn't work. It is not recognized by my computer. It connects and disconnects. I changed the micro USB cable, I updated the firmware of the board, I tried to connect the board in another computer, I also bought another board to check it, but It has the same problem.

I also want to say that the other USB connection works perfectly, that's why I could upgrade the firmware, but I do need to use the other one.

[KDJEM.1]

Hello @Mizael Alonso Pérez​  and welcome to the Community :) ,

Is the USB device detected by the PC?

Which error did you find? It is "error code 10" ?

Thank you.

Kaouthar

[MAlon.2]

Hello! Thank you so much!

It doesn't show any error code. I checked it in the COM port and It doesn't show anything. It's sounds like I'm connecting and disconnectig the device over and over again. I also want to add that I tried it with 3 different cables, boards and computers.

[KDJEM.1]

Hi @Mizael Alonso Pérez​,

Could you please:

Check your power supply and try to change your USB cable.

Also try to verify the LD7 and LD8 status:

• USB LD7: green LED indicates when VBUS is present on CN5 and is connected to PA9 of the STM32F407VGT6.
• USB LD8: red LED indicates an over-current from VBUS of CN5 and is connected to the I/O PD5 of the STM32F407VGT6.

Check connectivity options and the jumper position on the board (according to the UM1472)

May be this FAQ help you: USB device not recognized.

I hope this help you!

Kaouthar