STM32F4_Discovery failure when connecting to PC

[golddragon007]

Hi,

I have a problem with STM32F4_discovery, when I connect to the PC with mini USB, the device start work, with the last flashed program, but the windows says: Unknown device.
A request for the USB device descriptor failed.

What is the problem? How can I solvave it?

[Giovanni]

You need to install the ST-Link V2 drivers.

Giovanni

[golddragon007]

Where can I download and how can I install it? But...... I used this board yesterday and it worked, I connected to the PC and it know, its an ST-link device, but now its only unknown....
I don't thinks its driver problem... but I can try it.

[Giovanni]

If you already installed the driver then it can only be a problem with the board, the usb port or the cable.

Giovanni

[golddragon007]

Ohhh yeah, I found another cable, and I tried with it, with that cable it works... but what happened with the another one....