Whirpool Electric Double Oven

Question

We have an old Whirlpool double electric oven (wall mounted). The model number is RYE 2688P4. We cannot find the instruction manual. The oven has three timers - the first is cook time, the second and third are stop and start and they push in and pull out. Sometimes they are either pushed in wrong or pulled out wrong (we think one is supposed to be in and one out) and then the top oven doesn't work. Can you help us either by giving us a suggestion what to do or where we can get the manual? Thanks