|My thoughts exactly. The USB cord could certainly be bad, especially if it ever got pinched, the cable makes a sharp bend out of the machine or computer end, or is prone to being disturbed (moved, stepped on, pushed around, etc).|
It is also the easiest , simplest, cheapest, and most overlooked solution so give it a try first (or is that second?).
You have to be a little bit crazy to keep you from going insane.