ddj 1000 no sound from headphones

hi
i just bought a ddj 1000 today and im not able to hear some sound from my headphones if the sound of the speakers is off... so im only hearing sound from my headphones when the sound of the speakers is coming out. as soon as i put the fader of the channel down, the sound from my headphone also goes down.

the booth master cue button is ON, the cue button of the channel is also ON and i have download the drivers and frimware (updated versions)

anybody can help me plz?