My guess is you have fixed the problem already as most of the time it is the user at fault.

Did you check the volume of your media player?

If this was not the fault;

How often do you use headphones? You might have them still pluggend in but not on your ears (such a pity I have to give away my dearest secrets here).

Last but not least you might have a "short" in your headphone socket that prevents the speakers from getting involved.

Besides that how about the speakers are just gone bad?

Sorry have to go. My Sony does not even have a good sound so no bother ...

These are known for bad drivers....What OS are you using?

http://www.ehow.com/how_4817909_audio-problem-hp-mini-notebooks.html

I use external mini speaker on mine....

Well i m using Windows 7 . so, i dont think that must be the reason.

Because previously it was working well n good . It is since last few days. So, suggest me anything else.

You will need...

The most common problem I have observed is almost what post #1 said, except that its not a 'short', but rather an 'open' in the earphone jack.

When you plug earphones into the socket, it breaks a spring-loaded connection inside the socket to disconnect the speaker(s). When you remove the earphone plug, the spring should make the contact again. All it takes is one hair or a tiny dust bunny to prevent that contact, so there is a chance that simply blowing into the socket while pluging and unplugging the earphones will fix it. On the other hand, if you accidentally jerk on the earphone cord, like you start to walk away, forgetting that you are wearing the 'phones, it is quite possible to bend one or both contacts so that they don't reconnect when the earphone plug is removed. I have repaired one or two by opening it up and re-bending the spring, but I don't recommend that unless you have very good tools, dexterity, vision, and directions for disassembling and reassembling the unit.

The safest solution is the external speaker, as mentioned by SolarEagle.

Well , thanks for your suggestion but i would like to specify that problem persists without connecting headphone or earphones. It is the output of in build speakers that is verying which is causing problem for me.

Right! Once that connector has been damaged, it can't make good contact to the speakers. If it just barely makes contact, the current will vary with such things as temperature and the position of the computer. If earphones or an external speaker work normally, then you know the problem is in that socket. If not, then it is a driver (either hardware or software) problem.

Try running a virus checker