Are you getting any clicking noises from the back of the appliance or anything like that?
Also i assume you have tried the power button on the front control panel to see if it comes back on?
Ok if you have tried the power button on the front but nothing is comming on then it will be the main control board at the back at fault.
If you pull the appliance out and remove the metal panel at the bottom you will see the main control board on the far right hand side. This is the board that you need to replace and that should cure the fault from there.
Its quite a common fault on these whirlpool side by sides as ive replaced loads of them. But the odd time it has turned out to be the front control board itself. As theres no way of testing a control board its a case of replacing it. But for the fault you have 8 times out of 10 its the main control board at the back that causes this fault.
If you need anymore info just get back to me.
Are you still there?
Is there anything else i can help you with on this?