Question edited for clarity. Name of maker Simpson / Simson.
Question moved to Simpson category.
Good morning and Greeting down Under from the Great White North!
Unless you are going to get out your multimeter and trace the power, you are going to need a service call. They appear to have a history of failing control boards.
https://www.google.com/search?q=Simson+Ezi+Set+7.5kg+Simple+Wash+no+power
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How old is the machine is the biggest question here. It could be old enough that they circuit board that turns it on and off is bad. Yes, you can fix that yourself but you will need to take it apart and get to the board for a part number. Once you get this apart it most certainly would not be a bad idea to check and clean all connections. It is very often something as simple as a corroded connection or one that came lose over time with use.
Hello,
I am not an appliance repair perso, but I find that if you unplug items from the power supply for a minute or 2 most things reboot when plugged back in and powered on.
I do hope this assists you in some form.