Well in the end I replaced the PCB. The problem of stopping at various stages is gone now.
However there is a new problem after installing the PCB. Some of the buttons on the panel are not very responsive, I have to push the buttons really hard to make it work. One or two buttons are not working like the ability to select the cycle. I have checked the installation and PCB seems to be sitting correctly with the front panel controls.
Do I just have a faulty replacement part or there is a fault with my installation? The part does not seem to be a genuine LG part as the colours on the plugs were different otherwise identical .