Zanussi Aquacycle 1400 - FX 1465 W?

We have an Aquacycle 1400 ahd it has developed a fault.

When you close the door, select the cycle you want to use, press the start button and you here the "click" for the door locking, then it tries to lock again, and again and again. Withinn a few seconds, it bleeps 4 times and flashes the green light next to "end" - pauses for a few seconds and repeats the flashing and bleeping till you turn the cycle off.

Any clues?