wont charge or be picked up by iTunes

my iPhone 4. wont charge or be picked up by computer. Replaced the battery, all good with the new full battery, but it still not charging or being seen by iTunes. Thinking about replacing the doc connector, but not that hopeful, think it's one of the fuses!Bugger!!!! I'm not game enough to try & reset the charging fuse, I'm only good for part swaps, don't really know enough about what i'm doing to go mucking about with electricity.. Can anyone help me out with good (for dummies) instructions for doing fuse resets. i'm scared!!!