How can I fix my Beko DWD8560 w dishwasher?

My Beko DWD8560 w dishwasher has broken. It will fill with water, start to do a programme then stop and turn itself off completely, then turn on again and try again - but turn itself off again. It will do this over and over again at the same point in the cycle each time I try. Sometimes it eventually will manage to get past this and carry on, sometimes it gets stuck here for hours unless you intervene. I've tried it on the prewash - no heat programme and it works untill the end and then it stops and won't let the water out.

Please can someone help me?? I don't know what to do and it's out of warrenty by about 6 months!