Ben,
Good advice. It took me quite awhile to figure out that it usually isn't SGP :). I was also surprised how often things like cables, hubs, power supplies, etc, can fail in 'industrial' gear like we use night after night. It's nuts!
I always keep a couple USB cables around now just in case. Startech has been good to be for powered hubs (the industrial 12V model).
I recently swapped up my setup so that the computer is now resting on the telescope via a D-plate so there should be less movement with the cables (only a power cord going to it now). We'll see how that works when I get the new obs up.
Also, personal pet peeve, if you fix it, post how you fixed it! 
So many of these threads just trail off and I assume people got their equipment working. It helps people who do searches know what ultimately fixed your particular issue.
Take care,
Chris