|Plugging in headphones, unmakes contact of power to the speakers, and routes power to the headphones.|
Like I said, you likely have a female socket problem.
Those Laptop sound sockets seem rather cheap to me.
Try System Restore to a date when all was good.
Start >All Programs >Accessories >System Tools
Using System Restore too many times can cause
more harm than good. After doing a restore
that does not fix a problem, then UNDO the
Restoration, and try another restore point, or
just do the UNDO.
Other than that, you have a hardware problem like a socket.