Di2 Etube Upgrade

I have an ultegra 6870 di2 setup, with an internal battery, and recently connected my laptop to it running the latest etube software. The software indicated that a number of items could have a firmware upgrade so I went ahead and upgraded all that the software found. (I hadn't connected etube to the groupset since it was installed). Having done that a few weeks ago I recently connected the laptop and found that etube does not recognise anything - as it nothing is there. Any advice on what to do next re identifying what went wrong would be greatly appreciated.