Hotpoint wd420 WASH/DRYER door lock not coming on?

I have the Hotpoint WD420 Washer Dryer. The door locked light is not coming on. I replaced the electrical door lock and still the fault continues. It makes a noise as if the cycle is about to start but then after a couple of minutes the door locked light begins to flash.
I traced the wiring down to the main controller at the bottom of the machine...All looks in order but maybe it is faulty?? Any ideas what to try next?