Simpson Espirit 550 reset switch?

Hello. Can you help me? My washer turned itself off last night after an unbalanced load (this is normal). After a adjusted the load inside the bowl it refused to go again (this is the part that is not normal). It is not an electronic panel, just the turn knob one. Is there a reset switch or similar that I can push to get it going again? It is 7 years old now - is it even worth fixing? I have had no other problems with it at all.