If you want to go to a non touristy area of Madrid, but perfectly safe, go to the metro station Ciudad Lineal (line 5). Just outside the metro there is a mall called Alcala Norte and, in the basement, there is an appliance shop called Hermanos Perez. One of the most (if not the most) unexpensive shops in Madrid for that kind of goods. They also have another branch in calle Alcala, more or less at metro Quintana (North side of the street).