Welcome to Just Answers, I will be glad to help you with your question.
Does the display come on or is it blank?
If you are sure that you have power, then you will need to replace the CPU board. It should be displaying something if you have electrical power to it.
Here is a link to the part.
No, there is no protection that I am aware of, but I would still take it apart and follow the power wire from where it enters the machine to the board.
There is only one component before the board and its located in the corner of the machine. Its called the EMI filter, the power comes into the filter and right out. Get a voltmeter and check power coming in from the house and out of the filter. If none out , replace filter or replace board
Link to filter # XXXXX
Y9ou can search other sites for these parts and maybe get some better pricing.