If the machine is not producing heat, but the pigtail lights up when plugged in, it is possible that the machine has a bad fuse. 

Step 1. Diagnose if you have a fuse failure. Follow the steps outline in the document below to diagnose whether or not there is a fuse failure.

Step 2. Replacing the bad fuse. If the diagnosis is positive for fuse failure, follow the steps outlined in this video.