Dimension 4700 my headphones work fine but i cant

You must also plug in the power adapter for the speakers.

Boot from your RECOVERY DISK

Check to make sure all cables are connected. After this you will need to click on your sound card properties and set it to 5.1. which will allow all the speakers to play.

Please note you will need to have a card that supports 5.1 sound I do not believe the stock card in the Dell supports this feature which could be the problem.

Make sure the speaker connection is connected in back of the cpu. Check device manager to see that the audio and all hardware is working properly. Open up sound from the control panel classic view sound to see if sound is working. Just a couple of ideas.

you cant .... beacuse the sound cards are integrated however. my dimension 2350 didn't ... i opened it up bent a few of the contacts to the board around and now it works

buy a pci sound card and install it as a work around and disable the onboard sound in the bios.

1. Double-click the speaker icon in the system tray.
   
2. Verify that the audio settings slider bar is at least midway for all audio selections.
   
3. Remove any check marks that appear in the mute boxes.
   
4. Make certain your speakers are plug into the GREEN socket on the rear of your computer.
5. Check your speakers to see if their power supply is plugged in and functional.
6. Check in the Device Manager for a Splat near SOUND,VIDEO,AND GAME DEVICES.
7. You also might try System Restore and go back several days when you know for sure it was working.
8. Update the drivers from dell's site, there is only 1 Audio driver...here is a link to that page:
   

http://support.dell.com/support/downloads/driverslist.aspx?c=us&l=en&s=gen&ServiceTag=&SystemID=DIM_P4_4700&os=WW1&osl=en&catid=&impid=

If you need more assistance please write back.
Please leave a rating, thank you kindly

check http://support.dell.com/support/downloads/driverslist.aspx?c=us&l=en&s=gen&ServiceTag=&SystemID=DIM_P4_4700&os=WW1&osl=en&catid=&impid=
if you have a dell dimension 4700 like it shows this is the page with allthe drivers you can get.
you want to click 'Audio' -> 'download now' and then install that audio driver, that should fix the problem

Plug the headphones directly into the speaker port on the sound card, check for a mute button on the headphones. try another set of headphones to double check wether the first set is working.
regards..

The speaker output jack is green as indicated on the setup diagram which can be found here: http://support.dell.com/support/edocs/systems/dim4700/en/index.htm as for the speaker cable itself it may or may not be green. The other jacks are for various input/output devices such as mic, aux, etc.