I can't access my iPhone on iTunes

My iPhone is no longer showing up on "Devices" on my iTunes. When I connect my phone via USB cable, half the time it doesn't even react, and half the time it charges. Yet even when it's charging through my laptop, it isn't being treated as a recognized device on iTunes. Help is needed!

Methods I've Tried:

- Re-started iPhone

- Re-started Macbook

- Quit/Opened iTunes

- Re-installed iTunes

Extra Info:

iTunes 11.0.4

iPhone 4

iOS 6.1.3

Mac OS X Version 10.6.8