After changing dock connector I get "Unrecognized USB device.

At the beginning my problem was that I had to connect my charging cable ca 5 times until it started charging. When I connected it to my PC it was recognized as an iPhone, but I couldn't transfer anything and iTunes couldn't show its right disk space.

I decided to change the battery and the dock connector.

The result is that the charging connection works perfect, but when I connect it to my PC, I get "unrecognized USB device".

What did go wrong?