DIAGNOSIS The presets are just pre-programmed time/temp combos. They're based on standard, often frozen, food weights. If your portions are bigger or food is fridge-cold, they'll undercook.
FIX Use time and temperature controls instead. Start with the preset as a guide, but always add 2-3 minutes and check. For frozen foods, a good rule is 400°F and shake/turn halfway. Use a meat thermometer for chicken or pork—don't rely on the timer alone.
IF THAT DIDN'T WORK If manually setting a high temp (like 400°F) for a long time still doesn't cook food, the thermostat might be miscalibrated. Test by toasting a piece of white bread at 350°F for 5 minutes. If it's not golden brown, the unit isn't reaching temp.
HEADS UP These don't have a "preheat" indicator light. The element heats as soon as you start a program, but the chamber needs 2-3 minutes to get fully hot. For consistent results, let it run empty for 3 minutes before adding food when using manual mode.