John Smith for Model Number NX58J7750SS/AA My oven heats up to the set temperature, say 400F, then (often) slowly cools off. Example I set it to bake at 400F to cook potatoes. Only after 20 minutes I notice that they are not browning well. When I open the oven I can feel that it is not at 400F, it is cooler than that. The digital thermometer on the dashboard however shows 400F. So I turn the oven off), and back on again. Set the temperature to 400F again, then it shows that the oven is 320F. Then it slowly warms up to that temperature again. I have only noticed this for the upper oven, not the lower oven.
Answer John, You will want to test the oven sensor on the unit. You will want to check at room temp for a resistance of 1090 ohms. If the resistance is good you can test it at 400 degrees and the resistance should be 1736 ohms. If the resistance is not correct replace the sensor. If it checks ok then the main board will be the issue. Read More... Answered by AppliancePartsPros.com | Friday, July 28, 2017