Tried to google the hell outta this problem but I can't find anything specific enough.
Just got a Dell Vostro 1540 laptop from a school I'm attending. The problem is it doesn't support external speakers. It has a headphone jack but apparently the way its set up it only uses the headphones for things like skype, etc. Everything else it only plays through the crappy little built in speakers, Sounds like a firmware issue to me since its simply a matter of the codec telling the sound part of the MoBo what to do. It should have the capability of sending sound to external speakers but it won't.
Computer is brand new outta the box, still under warranty, running Win7 Home Premium 64 bit.
Otherwise its a great little laptop but it seems to be internally configured to be a "business guy in a meeting" kinda laptop.
**Update** Hmm, plugged in the headset I use for TS and selected the headset as my default audio device. Seems to have solved it for now. Weird...regular headphones wouldn't work but a headset with a microphone does.