no audio output through headphones

hello,

i have been using my DVX100a for a while now and everything has been great. last two shoots, however, i cannot get any audio through my headphone jack. the camera is picking up sound- the audio meters read and in the final output there is audio. i turned the volume all the way up on the camera and nothing- even when i pull the headphones out nothing comes through the speakers. i looked for a mute button, which i assume is the issues, but haven't found one- not even mentioned in the manuel.

i thought maybe it was my headphones, but i changed them and nothing happened. but headphones were actually earbuds, but they have worked in the past.

anyone have any recommendations?

thanks,