Frigidaire Oven Not Maintaining Temperature

Our Frigidaire oven has always maintained temperature very well.

Recently it started dropping 5 degrees from what the reading was on the clock/temperature setting. Suddenly it is now approximately 15 to 20 degrees below the reading setting and I am unable to heat the oven past 350 degrees.

Where would you recommend I begin to troubleshoot this problem?

Any help is much appreciated.

Here are your pats
http://www.appliancepartspros.com/partsearch/modelsearch.aspx?model=GLEF378CSB

Here is the wiring diagram
[http://www.applianceaid.com/elecrange.html](http://manuals.frigidaire.com/prodinfo_pdf/Springfield/316255318.pdf"]http://manuals.frigidaire.com/prodinfo_pdf/Springfield/316255318.pdf[/URL]

I would unplu/remove power from the unit for 10 minutes or so to see if it will correct itself.

Next check that both elements are OK.

Then check the temperature sensor for loose dirty connectors and proper resistance.

Here is a good link with basic stove repair help.
[URL="http://www.applianceaid.com/elecrange.html)