sounds like the heating elements in the oven have blown,so thats why electrics dont work, dont turn on any power to that cooker, but you can use the gas, but you will have to light it yourself, not sure but some rangemasters have two heating elements in them one in the top of the oven and one in the bottom. you will have to replace the blowning one, with a new one of the same size shape and power rateing, not hard to do if you can get at them, (WITH ALL THE POWER OFF) to that cooker, i had to replace mine, in a smaller cooker, 40 pound for the element. good luck stay safe...
j, May 2014
