zanussi ZT 617 Dishwasher. Alarm code A7?

To add to my question about a broken shower! I now need to ask for some help with a dishwasher that i fear may have just come to the end of it's life. It's between 8-10 yrs old. It tries to start up but then just stops and gives me the alarm code A7, to which the mannual says call an engineer. Being a single mum at xmas, the last thing i need is call out costs just to be told the machine is past it! A friend suggested I should try this site as they have had good advice previously. If you have any ideas i'd love to hear. Thank you!