Gas or electric?

Here are your parts
Parts for Frigidaire FEB30T7FCC Wall Oven - AppliancePartsPros.com

Here is a wiring diagram
http://manuals.frigidaire.com/p...assomption/318046123.pdf

[COLOR="Blue"]after using the self clean (at different times) the top oven only the broiler comes on,[/COLOR]
I am assuming that the unit either stays in preheat or takes a long time to come ready.
Could be a blown element.
Remove power from the unit.
This is very important because on most units there is still voltage to one side of the element even when it is turned off.
Undo the screw/s holding the element to the back of the oven.
Carefully pull the element into the oven.
Remove the wires from it and check it with a meter.
Should be around 25 ohms.
It is a good idea to clip something (clothespin etc.) to the wires so they do not disappear into the back of the unit while you are checking the element.
If the element is OK check the wiring going to the control board.
If that is OK then odds are that the control board is shot.

[COLOR="Blue"] the bottom oven nothing comes on, doesn't heat up at all[/COLOR]
I am assuming that the control shows that the unit is in preheat and it never comes ready.
Odds are that you blew the thermal circuit breaker (item 119 in the Lower Oven Parts section).
You should be able to reset it by pushing it's red button back in.