So about a week ago I started getting that message randomly popping up that says "this accessory is not supported by this iPhone" when nothing was plugged in. I ignored it up until 2 days ago it stopped charging, so I looked into it and read that I need to clean the dock. So I gently cleaned it and at this point the phone was at about 10% battery left. I plug it in to charge and it charges for a split second then the battery turns into the plug as if it was fully charged. After the battery died the screen is just black and won't charge or power on. I don't have warrenty on it. It's a Jailbroken iPhone 4. Any help would be greatly appreciated. Thanks!