problem with connecting the board by usb

Hi,

I have a problem with my new Intel Galileo board.

I have done a circuit with optocoupler CNY70 like at this picture:

I loaded a simple program to use this sensor. Then I disconnected a cable from A1, because I wanted to connect it with A0  (I noticed, that set A0 in the program.)

Then I heard the sound of disconnected usb. Now the usb led on the board is not light. I also can't connect the board with my computer, because it isn't visible.

Is it posible to do a short circuit and demage the board by disconnecting this cable ?

Does anyone know, what could cause the usb problem on my board ?