Just to give an update, the new pcb arrived early last week but when the engineer fitted it, another fault code appeared and the unit would not run. CH35 appeared, which I believe relates to a pressure sensor fault. I am accordingly now seeking a new sensor and hoping that will resolve the problem. Apparent on removing the old pcb was evidence of a short circuit against part of the chassis due to lack of insulation. There is a suggestion that these short circuits are a known problem for LG in these machines.