Disclaimer: this is not a normal "how do I fix it" question.

This range is in really good shape, except the timer/controller died. All it would do is flash F8 (if I recall correctly). Every place I looked to get a new controller told me it was discontinued and there was no replacement.

Another person would have gone shopping for a new range at that point, but I'm an electronic engineer, and I make industrial controllers for a living, and I just hate to admit defeat when I don't have to :).

So I studied the schematic and the user manual and designed a replacement controller. The power control relays are configured the same as the original design and it uses the same door latch and temperature sensors. But it uses a relatively powerful microcontroller with an accurate temperature measurement system and uses a touch screen as user interface.

Everything seems to be working as planned; I can turn on the bake and/or broil heaters and read the temperature reliably. I can enter a temperature setpoint and watch it drive to that temperature and stay there.

The problem is that I really don't know how it is supposed to operate. For instance:

• in BAKE mode, do I run both heaters or just the lower one?
  
• in BROIL mode, do I turn on both heaters up to a point, then only run the top heater?
  
• the user manual doesn't show any temperature setting for BROIL mode. It seems like it should have an upper temperature limit.
  
• I assume that SELF CLEAN turns on both heaters to a very high temperature for a certain amount of time. What temperature and time?

If anyone could help educate me, I'd really appreciate it!
Thanks,
Ray

HumboldtRepairMan - thanks for the reply.
Are you saying that for BROIL mode, I turn on the top element and regulate the temperature to a fixed setting like 500 degrees? Or should I allow the user to set the temperature in BROIL mode just like BAKE mode? (If it's not obvious yet, I'm a much better engineer than cook)

The temperature probe is just a sensor to tell the controller what the actual oven temperature is. The knob is just another sensor to tell the controller what temperature you want the oven to be. The controller is what turns the heaters on/off in such a way that:
actual_temperature = wanted_temperature

In the user manual for this oven, it says that when the user selects BROIL mode, there is no temperature setting - at least not one that the user can set. But I think there must be an internal limit that the controller uses to keep the oven from getting dangerously hot. I just don't know what that limit is.

Thanks,
Ray

Um, OK, sorry if I ruffled any feathers. Perhaps this is the wrong forum to ask these questions. Or, as you suggest, perhaps another tech can help. But thanks for your time.