The cable just stopped worked one day after my MBP had run out of battery.
The new cable was bought off eBay, but it said Foxconn and looked exactly like the one I pulled out.
Don't really know how to check the connections. Can you run any hardware test to test this or something like that? Don't have much knowledge of the hardware, just followed a guide on iFixit.com
And yes, I have 10.8.3.