I had a similar problem, I my case I identified the cause as a lose fitting socket in my laptop. Tried different USB cables and the only ones that worked were a tighter fit in the laptop socket.
The following youtube video I found explains how I fixed my problem, but this problem may not be the same for everyone so be very careful if you follow this video -- serious damage could result.
https://www.youtube.com/watch?v=B_ruqSrkxNU