Good Day.
I have a 8 or 9 year old Frigidaire wall mounted oven, Model CFEB789CCB-1 in my house up here in Vancouver Canada.
I recently heard crackling sounds that seemed to be coming from behind the LED control panels. It was not the sounds of relays clicking on and off. It was a bad crackling sound. Upon visual inspection of behind the LED control panel - no evidence of short circuits or hot spots - at least visually.
The lower element is about a year old and does not heat up now. The old element burned out. The newer lower element appears to be in good physical shape - no shorts - 25 ohm resistance across the element.
There is only 18 volts across the power leads feeding the lower element, measured when I remove the heating element and call for bake, which should turn on the upper and lower elements.
The upper element works fine, gets hot and receives 240 volts. The convection element and fan on the back wall work fine.

The only problem is the lower element doesn't heat up and has only 18 volts AC across it.

All three glass fuses are fine. (30 amp / 15 amp / 30 amp)

Any ideas? A previous contributor suggested the lower control switch. I am a very handy guy capable of replacing this stuff, but the trouble is always with the diagnosis.

Any help is appreciated.
Regards,
Roman

RomanMa - When you checked the bottom element, with yhe ohm meter with power off, did you disconnect one of the wires on the element?? If you didn't, then you got a false reading, as to contituting, of the element,Try doing it this way,and see if you get no reading on the ohm meter( ,IF YOU Don't GET A READING< THEN THE ELEMENT IS BAD)It's better and cheaper to make sure before replaceing the control switch, then finding out it was the element,all the time. Also make sure your ohm meter is set right, I myself have at times, had mine set wrong, but I always doubled checked to make sure I hope this helps,Good day & good luck, GOD BLESS:::::: F.B.E.

Thanks for the quick response F.B.E.

I checked the resistance across the now 1 year old lower element with that element out of the oven sitting on my kitchen counter. I used a digital ohm meter on the lowest resistance setting (0 - 200 ohms). That's where I got the 25 ohm reading, which seems to be in the 10 - 200 ohm range that people often mention for resistance type heating elements for ovens.

I also turned the oven on to the bake setting, which I believe is lower and upper element normally both on during the heating cycle. I did this with the lower element out of the oven and my multimeter clipped to the dangling leads of the lower element feed wires.
This is how I measured the strange 18 volts AC potential. I would have expected either zero volts for a control fault or 240 volts for an element failure, not the 18 volts AC across the 2 hots. That I don't get!

I get a full 240 volts at the glass fuses when I remove the two 30 amp glass screw in fuses and measure the potential across those 2 legs. The fuses are good as well. I tested those for conductivity with the ohm meter.

So I am running out of ideas.
I suspect the relays that are built in to the all too complicated circuitry that operates this 9 year old oven.

Any ideas?
Thanks for the help.
Regards,
Roman

Start working backwards testing the voltage. This way you will be able to tell where you are losing the voltage.The cracking sounds you heard seem to me to be electrical. Check all the wiring and connections involved in the lower element. You should find a wiring diagram somewhere in the control section of the unit.

Thanks Esquire1 ;;;; F.B.E.