First thought.  If you have a combination headphone (earphone) and mic, that is usually on a "TRRS" plug.  You need "TRS" plugs, one for the headphone and another for the mic.  There are adapters available that will provide this.  But, it depends on what type combination you have.  If its the type for a cell phone, forget it as it usually will not work even with adapter.  
Inspiron n5010 Issues with ear phone microphone. I have a dell inspiron n5010 which is very old but still works, but i have a issue with earphone mic means when i insert earphone in 1st jack the sound comes in the earphone speaker but in any meeting if i use that earphone the sound goes from laptop microphone which is a little bad because it takes laptop fan noise also with it.so there are 2 jacks so then i tried with second jack but then no sound came nor the mic worked but the same earphone and its mic are working fine in another laptop, So pls anyone tell how to resolve this issue as soon as possible.   2 Jacks Img.. [IMAGE]The first jack is external microphone and second in head phones..
Inspiron n5010 Issues with ear phone microphone.