Hello and welcome to Just Answer my name is ***** ***** I will be the one who tries to assist you today. I am sorry to hear you are having trouble with your appliance sadly this can be a very common issue with this brand.
Try this, unplug the machine for 5 min. and plug it back in, see if the board resets and it starts, let me know.
I am attaching this link which provides the part you will need in the event the reset does not help.
You cant just change the button unfortunately you will need to replace the interface.
You can order this at the following link,
they did have issues with those, hope this helps.
The only other possible thing that it could be is the control board may have gone bad which the part alone can cost up to 165 dollars. I would personally suggest having a repair man put that in though but of course they will charge you a labor fee as well.
I certainly hope my advice helps and if you have any follow up questions I would be more than happy to assist you. If you are satisfied with your answer please rate with 5 stars.