Hmm. I have the same problem, started yesterday.
I am still covered by extended and complete care. I hope it covers this. I'm not exactly a soddering wunderkid.
I think there is a problem with Dell;'s speaker jack which affects sound card. I had trouble with sound thru external speakers one night and then the next day no sound. Badd soundcard If sound card is bad entire motherboard has to be replaced
Call tech support they will walk you thru process to determine if it is the computer or you This is the 3rd Dell this year that I've had hardware problems with
I've got another solution...
I have an Inspiron 8600 and a friend has an 8500. Both of us have experienced this problem. It has occurred to both of us when we inserted the plug from our headphones into the speaker-out jack on the computer. In the headphones you hear a "static zap" and zappo, the sound is dead. I tried it once with the sound playing though the laptop's speakers, inserted the headphones, the sound became low & distorted in the headphones, pulled out the headphone plug, and the sound was still low & distorted.
I fixed the problem by updating the BIOS (the first time it happened, I updated the BIOS to the latest version, then the next time it happened, I just re-ran the same version update... I think there is an ESD problem with a static zap to the speaker-out jack somehow zapping the system's BIOS NVRAM. Since others have fixed the problem by running the Dell diagnostics program this seems to confirm this. I wouldn't doubt this program examines errors in the BIOS and resets it.
Any other thoughts out there?