Baumatic BDW11 knocking off tripswitch

Been to look at a Baumatic Integrated Dishwasher BDW11, it is not accepting programmes when you select them. On switch on bell rings, but no programme led’s light up. On/off led does not light, but supply is OK on load side of switch. If i switch off, i can enter programme, just for a few sec’s & then leds in programe sequence light up, programe does not function correctly, most times tripswitch goes off. This happens with heater, disconnected, pump, disconnected & circulation pump disconnected. There is no water in base of machine & loom looks good in door etc. Any ideas?