You mentioned that you replaced the line cord to the machine - Did you replace the cord cap (The end that plugs into the wall) or was it a molded end piece that you didn't have to mess with?
If you installed a cord cap, open it back up and make sure you don't have a whisker (single strand) of the wires out of place.
If this is a new cord with a molded cord cap, use a meter on the 20 M setting and measure from white to black, black to green, white to green. You should see high (near infinite) resistance. If not, then disconnect the end of the cord inside the machine and measure again. If you do not see infinite, you got a bad power cord.
Assuming the GFCI is good, then there has to be something wrong with the cord or cord connection. I don't see anything jumping out at me in your pics.