Did you place food in oven before preheat cycle was complete?
For optimal performance, place food in the oven as soon after the signal as possible.
CLICK HERE for video on Oven Pre-Heating.
Did you open the oven door to check baking/cooking results?
Always use the oven light to check cooking/baking progress because opening the oven door heat to escape and the oven to cool.
CLICK HERE for video on Oven Door Opening.
Has the temperature been set to Celsius instead of Fahrenheit?
The temperature in the oven(s) is preset to Fahrenheit, but can be changed to Celsius. If the oven has accidentally been changed to Celsius, the oven control will not exceed 260°.
What type of Bakeware are you using?
The bakeware material effects cooking results. Follow manufacturer's recommendations and use the bakeware size recommended in the recipe.
CLICK HERE for video on different bakeware.
How many pans were on the rack? How large of pan were you using?
Hot air must be able to circulate to cook food evenly. Allow 2" of space/clearance around baking pan(s) and the oven walls.
Was an entire oven rack or the oven bottom lined with aluminum foil?
Do not cover an entire oven rack or the oven bottom with aluminum foil below the baking pan. This can block good air flow.
CLICK HERE for a video on the effects of airflow.