Radio cutting out

[Woody]

Hi, having an issue with the stereo in my 2010 insignia, it's the 400 stereo. It has a mind of its own, you start the car up and the stereo goes off, taking the display out with it. It will stay off for anything between a minute to 5 minutes then come on and go off again. It'll do this 3-4 times usually before it decides to come on and stay on for the rest of the journey. When the display goes off with the stereo then the "clicks/beeps" you normally hear from the indicators as they are being used are silent, until the stereo pops into life.
I have done the google searches etc and the usual story, people with similar issue don't post up there final findings etc
I've looked through my Haynes but I can't find any wiring diagram relating to the stereo. I've pulled the stereo out and checked all connections behind it and the display, all looks fine there.
Another person who had a similar issue, reported a problem with there key fob being stubborn to lock/unlock the car unless very close and in a particular way. ( mine also does this) I changed the batt in the fob twice thinking the battery was low, but made no difference.

Could this be a body control issue? And can anybody point me in the direction of a stereo wiring diagram to trace wires etc.
There does seem to be a software update mention in other posts but those posts are 3 years old now.
Any advice anyone?
Thanks