Why does my Hotpoint Aquarius WMA31 keep cutting out?

Bought this second-hand (was assured it was in full working order from company purchased from) few days ago. The water goes to and from the drum fine, the programme starts as you would expect however 30sec-1min in it the lights (which until this point are on as normal) flicker and the whole machine cuts out. I'm guessing there is a faulty connection somewhere? Anybody have any ideas/has dealt with this before? An engineer was supposed to be sent from the guy I bought it from but he's being difficult.