I have what looks to be a bad gfci outlet in my kitchen. My house was built in 1989, and this is the original outlet. The reset button doesn't stay in the reset position. All the other outlets (standard outlets) in the circuit are dead. When I pulled the outlet out of the wall box, I noticed a black and white wire coming out of a hole in the back of the outlet, obviously the way it was manufactured (this was in addition to connection points on the sides of the outlet). Those wires are then connected to the circuit via wire nuts. My question is, would the wires coming from back of the the outlet be the load or the line side? There seems to be no distinguishing markings to say so. The new outlet I have purchased has all of the markings and yellow tape across a pair of the connection screws.
Got it replaced. Was an old General Electric model, I think the part number is E-42190. All connections used wire nuts, The wires in the center of the back were line. Two wires on the side were load and ground. I just needed better lighting and my microscope glasses to see it. Very small print. New Levitron model was very clearly marked. Thanks to all who answered.