Please help me out

[rushimusic]

So i m using Mackie CR3 studio monitor speakers they were working cool earlier but now only whenever i plug in the headphone jack the sound is through earphones only when i remove there s no sound from speakers i tried opening them checked the wirings n stuff they are all fine and also i m checking the aux and earphone jack in which i think earphones jack s sensors not working how can i fix this

 

[americanaudiophile]

It is possible that the mechanical mechanism in the headphone jack that cuts off the monitors is stuck. If you can see the headphone jack from inside you should be able to tell.