Well, it looks as though I will be seeking further help from Wanhao UK as the machine will not get past the first couple of layers without resetting itself and stopping in its' tracks. It was going so well for a few weeks and then started playing up again. I have checked the connectors to the mainboard, so it is looking more like a mainboard fault, which will be a titser at £150 to replace.

Any ideas what I could test, bearing in mind that this fault only shows itself after a few minutes printing ?