Being busy this hasn’t been given much time. I put it in the corner of the workshop and monitored the drain, there was none. All codes cleared and none returned. I drove it on Thursday and Friday. It was ok until Friday lunchtime when the cluster started to drop out. By drop out I mean go completely blank. I stopped when it was blank and gave the dash a thump, the display returned. A few more thumps confirmed it plays up.
It seems very like a dry joint so I will strip it and check. It wold be nice if someone had seen this before and could point me in the right direction.