MK7 Fiesta Infotainment turns off

[Uncle Festa]

I have recently purchased a 2009 Fiesta Zetec and been slowly modifying it. Lately I have noticed that the central infotainment unit turns off then after some time will come back on again.
It had recently sat for a few days and when I went to wash it the infotainment system was blank with no response.
The following morning I went out to pick up some things and it was working but on my way home it turned off again.
I stopped and filled up and when I got back in to drive home it was working again. From what I have seen around the world this is a common issue.
Anyone can give some tips on what the issue is to save me a trip to a sparky or Ford dealership?