The Samsung M171FN/XEF Oven has some known problems that occur often. Here are some easy to do solutions for the problems or error codes your Samsung might be giving you.
Defective primary interlock switch or defective contacts of timer switch
Defective drive motor
Fuse blown out, poor contact of power cord, defective lamp, defective timer contacts
Defective fan motor
Oven lamp and fan do not turn on
Open cathode of magnetron
Defective contacts of timer
Broken door hinges