I think the oven control board is out. The elements are good they ohm out, I only have 120v to elements (ground to each side of element) The stove top burners work, just no oven elements will not heat up.
Here are your parts
Parts for Frigidaire FEFL79HBB Range - AppliancePartsPros.com
Here is the tech sheet.
http://manuals.frigidaire.com/prodinfo_pdf/Springfield/316519936en.pdf
I agree with you that the control board is the most likely culprit.
I would unplug the unit and check the wires from the control board to the elements just to be sure they are OK.
If OK I would replace the control board.
You may also need a control overlay. Often they do not come off without some damage. Warming it up with a air dryer sometimes loosens the glue enough to get it off OK.
I am assuming that the oven stays in preheat and never comes ready.
SOUNDS LIKE YOU HAVE TO MAKE SURE SOMEONE CAN SHOW YOU WHERE TO PUT THE WIRES SO THEY ARE ON DIFERENT PHASES!!!240 REQUIRES 120 COMING OFF TWO SEPERATE PHASES