STM32F4 DISC Usb not recognized

[lre.1]

I have STM32F4 DISC board and I worked with it several weeks. It was working correctly but today when I was set a SPI connection with other stm32f030 mcu, I plug-in and plug-out usb cable and I got "USB device not recognized" error message.

I didn't change anything. 

When I was plug-in, power led on board lighting dimly. Is this a sign for corruption of card??

stm32cude ide can not detect stm32 disc board.

Thanks for any help

[Karl Yamashita]

Have you tried restarting your computer and/or docking station? Every once in while I get similar warnings and after power cycling my docking station, the USB ports start working again. 

[Pavel A.]

> I didn't change anything. 

It just happens to things. Suppose you have a hard drive full of valuable data. All is good, then suddenly you hear a subtle click click and it is dead. 

[lre.1]

I restart computer and also uninstall and install driver st-link v2 but. doesn't change anything.

Power Led and LD8 led always on. 

I found something : "LD8 (red LED) indicates an over-current from connected device", is this related my issue ?

[lre.1 · Accepted solution]

Hello again.

I connected external power (5V and GND) to on board pins and board started working correctly.

If I disconnect external GND cable from board and only 5V cable connected on board. Card continued working correctly :flushed_face: . It was interesting

Which component corrupted on board? Any suggestion?

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I found fault on D1 (BAT60JFILM) diode, if I short circuit it board can working.