Saw this dock in DollarTree, gave it a try, neither charge nor sync worked. Then saw the micro USB cable, looked like very good quality, gave it a try, both charge and sync worked like a charm!
Replacing the cable is very easy, no any special tool required, no soldering. The dock is very easy to open, no screw, no glue. The only little trick is to add a small piece of carton to the plug seat which is 1.5 mm thinner than the original cable's.
Watch this video for the procedure: