Indesit WEI 167 will start then wont start?

Indesit WEI 167 will run normally for a few weeks and then wont switch on at all. This is solved by first pressing pressing the main power switch then the machine start button and LED 1 then 2 then 3 and back to 2 and 3 then main switch then functions and machine runs ok. The only spurious light is the LED 2 which is "extra rinse " which lights up on its own. PCBs have been inspected and appear to have no blown components , door swictch has 8ohms and wiring checked for continuity.