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Replacement parts for FRIGIDAIRE PLEB27S8CCC Frigidaire/wall Oven | AppliancePartsPros.com

Here is the wiring diagram
http://manuals.frigidaire.com/prodinfo_pdf/Lassomption/318046220.pdf

This may also help but it does not list your unit
http://frigidaireservicetips.com/pdfs/481_18.pdf

Does the broil element (upper) work?
Does the unit look normal but the lower element never comes on and the oven never comes ready?

If neither element comes on, it could be the thermal circuit breaker is shot (open/infinite ohms)
If the unit comes ready right away it could be the temperature sensor is no good.

That the convection seemed to work a little is puzzling as I cannot find a separate convection element in this unit.

Does the unit stay in preheat or does it show that the oven is ready?
if it comes ready then the problem will be with the oven sensor or the control board.

Yes it could be the thermal circuit breaker.
Note that it looks like it is resettable re: the little red button will pops out if it trips. Push it back in to reset it.
Even if it is not tripped I would check it with a meter.

The first thing to check is the power.
The elements require the full 240 volts.
Try flipping the breaker off/on slowly, sometimes you can loose half the line without actually tripping the breaker.
If this does nothing, check the voltage at the plug
L1 to L2 should be 240 volts
L1 to Neutral and L2 to Neutral, both should be 120 volts.
If OK
Unplug the unit and check the wires at the terminal strip in the machine to make sure none are loose or burned out
If OK
Check the power at the terminal strip.
[COLOR="Red"]Be careful as 240 volts is lethal !!! [/COLOR]

If OK then check the thermal circuit beaker.

If OK then it leaves you with a bad wire, a bad DLB relay or a bad control board.