Unhappy USB not working

Hi everyone i have had the Samsung galaxy s 2 for few months and loving it but few weeks ago i been getting random connected and disconnected saying that it is charging but there is no usb cable even plugged in to the phone, i have used compressed air and small little brush hoping that will sort it but sadly not

im thinking it will have to be sent to Samsung to get it fixed but though my phone is rooted.

hope someone could help me