Line in mic stopped working: only array mic now works

Hi, 

I have a Dell N5110 running on Windows 7 64 bit, and I've been using an awesome noise cancelling mic for 9 months for go to meeting conference calls, skype, etc. for 9 months and it suddenly stopped working. I can now get audio through the headset speaker but the line in mic won't work; audio recording will only come in through the mic array (which is terrible sound you really can't hear). I've looked through the FAQ forum, changed my settings, looked into the control panel, and can't find anything that seems to work. Could it be recent updates? Do I need to reinstall drivers (ugh)?

Thanks so much,

Missy