Does it power on, and just refuse to start the engines? You might want to turn everything off. Turn on your remote first, and wait for it to fully boot up. Then turn on your drone.
I recommend calibration of the compass before the first flight of the day, and at any new location. Sometimes the location itself with cause "compass interference" so...even with calibration, the engines will refuse to start, and you will get an error message as soon as you set the drone back down. You could try launching from the Karma case, or moving a few feet as that sometimes helps.