Temperature:
Is that 39 degrees in Celsius or Fahrenheit?
If it is celsius, your incubator is a little too warm, and the temperature needs to be turned down a little bit. Chicken eggs are supposed to be incubated at 37-38 degrees celsius.
If it is fahrenheit, that is about as cold as a refrigerator. If you have the incubator inside a house, it should not be possible for it to be that cold unless the house is also as cold as a refrigerator. An incubator that cold inside is probably not making any heat at all, so that would mean a broken heating element.
Humidity:
Have you checked the humidity gauge to see if it is accurate? Some styles can be calibrated (to see if they are right, and fix them if they are wrong.)
You can also check humidity just by incubating eggs, and candling them at intervals. There are charts showing how big the air cell is supposed to be at 1 week, 2 weeks, and just before hatch. If you candle the eggs and the air cell is the right size, then you know the humidity was right. If the air cell is the wrong size, then you know the humidity was wrong. An extra-big air cell means it was too dry, so add more moisture: maybe more sponges or a cup of water. A too-small air cell means too humid, so add less humidity.
Incubator-specific:
If you can post a picture of your incubator, or list the brand and model, someone may have advice for that specific kind of incubator.