My parent in-law's Fisher & Paykel DW60CSW1 dishwasher stopped working. When you turn it on all lights came on but none of the buttons did anything.
The problem was caused by the door switch and is usually easy to fix.
Warning: disconnect power before you do any work on the dishwasher as there are dangerous voltages inside.
To access the door switch you need to remove the screws from the rear side of the door. Take out all the screws at the top holding the plastic control panel first then start removing the screws that hold the rest of the door on. You should only have to remove a few of those before you will have enough clearance to access the door switch.
The door switch is held in place by the two screws at the top of the door. Once these are out you can remove the door switch, then disconnect the two wires attached to it. It doesn't matter which one of these wires connects to each connector of the switch.
The problem with this switch was not the microswitch itself, but the plastic part of the switch which had deformed slightly over the years and the pivoting part of the switch which activates the microswitch was not pushing the microswitch down far enough.
Once you have it out you can test the switch with a multimeter. When you push the plastic pivoting part in (it will lock into place in open and closed positions) you should have full conductivity. If you don't, remove the microswitch from the assembly and test it on its own.
The best fix is a new complete switch mechanism but I was able to fix this one by jamming a piece of plastic underneath the microswitch to lift it high enough to make better contact. I then used a cable tie to hold it all together.
The following photos of the switch were kindly supplied by a reader, Shuey. They show the switch, how it is held in place, and how Shuey fixed his with a bread tie. Thanks, Shuey!