How to fix my Servis Washer dryer 900?

My washer dryer is 10 yrs old and is currently working sometimes. When I apply the wash setings and turn it on, the light comes on and then nothing happens. I have tried turning it off at the mains and then retrying it, but no luck. we have checked the door and still no luck. We did this on and off on saturday and finally got it to work at night however i have been trying all day today and can't get it to work. Please let me know your thoughts.
Thanks