Trouble with audio jack. Plays on speaker but not on headphones! Help?

I am running on a Dell Latitude D630. Just recently my audio jack isnt wanting to understand that my headphones are plugged in. I know that my headphones work cause when I would play them on my iPod they would work perfectly fine. I went into my drivers and uninstalled then reinstalled the audio drivers. I looked for other solutions online and there were none that fit to what I was looking for. the only sound that comes out of the computer are the stock "High Definition Audio Device" speakers.

At this moment I have plugged in 3 sets of headphones and none have been able to get sound out of the audio jack. They are all the simple 3.5mm plugs and I have used them numbers of times when making music on FL Studio or listening to music on Spotify. I know that there has to be a solution because there has never been a problem like this before.

Thank you for any help that you can give me

If you are not using the Dell supplied sound drivers that can be a problem. I used to do a lot of support on the Dell forum and we found that non-Dell drivers either did not work or did not work properly on many Dell's.

Here is the Dell Vista/Windows 7 SigmaTel sound Driver.
Drivers and Downloads | Dell [United States]

I tried to use this. And i installed it and nothing happened. The headphone jack isnt letting me hear sounds from my laptop. Everything is still going through the speaker, and not through the headphones. I even tried updating all my drivers and nothing is wanting to play. This is what it says on my playback.

The "High Definition Audio Device" suggests you are not using the Dell SigmaTel sound drivers. Using the Dell drivers is still the first step. There may be other problems but the Dell drivers (properly) installed is the first step.