No sound all of a sudden

Since this just happened, use the System Restore function and restore the PC back to a date when it did work.  System Restore can be accessed from Start/Programs/Accessories/System Tools.  System Restore will not delete any user data or e-mails.

Thanks.  I've just given that a try and restored to 2 days ago, when I know the sound was working, and I'm still not getting anything from the speakers on my laptop.

Dell will fix it because it is a hardware problem but you might have to jump through some hoops (such as doing Factory Image Restore) because Dell Diagnostics indicates it is a software problem and you might have to let tech support exhaust all software solutions first. But Dell has fixed it for a lot of people ... they just seem to do it as a last resort without understanding the nature of the problem imho.  Except for models that have a jack daughterboard the solution is to replace the motherboard which they naturally don't want to do without trying all other possible solutions.

I've also checked the volume and the settings in control panel, and everything is as it should be.  The headphones are working, so I know that sound is coming out. 

I tried a diagnostics just before posting and the speakers are working; sound was coming out.  It's just when Windows loads I get nothing.

If you reinstall the audio driver with no luck then here is a possible explanation for this combination of symptoms:

    * Speakers don't work and are not muted or deselected
    * Headphone jack does work
    * Reinstalling audio driver does not help
    * Audio test in Dell Diagnostics passes
    * On models with 2 headphone jacks, one may be "checked" in the control panel as if in use


The Dell laptops with 92HD audio utilize IDT's Universal Jacks technology, which is somewhat complicated. In addition to the usual mechanical parts, the jack also uses current & impedance-sensing techniques to trigger software configuration and switching (to send the audio signal to the speakers). So there are three areas of potential failure: mechanical, electronic, and software. Sometimes, a little very gentle wiggle of a plug in the jack will get it to resume normal functioning, at least temporarily. There is a sensing pin in the jack (Sense_A pin) that is used to detect the presence of plugs and it can be the cause of failure to trigger the software switching. Failure of the sense pin usually results in the computer behaving like there is always a plug in the jack.

Normally the audio test in Dell Diagnostics would confirm that there is a hardware problem, but the Universal Jacks can cause a false result in Diagnostics. That is because Diagnostics operates in DOS, outside of Windows, so a Windows software misconfiguration is irrelevant to the test even though in this case it is caused by hardware. So the audio test can pass in Diagnostics, correctly signaling that software configuration is the immediate cause of the problem, but missing that a hardware problem, the bad jack or sensing pin, is the root cause. In these instances the only reliable diagnostic procedures are to try a new motherboard (or jack daughterboard on the models that have them) or to use PC Restore (called Factory Image Restore in Vista) to restore the computer to its original configuration as shipped from the factory. If the speakers still don't work after PC/Factory Image Restore then there is definitely a hardware problem even if it passes the normally infallible Dell Diagnostic audio test.

Thanks Jimco.  I just found your other post through Google about 15 minutes ago and I now have sound again after shaking the headphones in the jack :emotion-2:  Will Dell fix this problem if it happens again?

Jim, thanks very much for the answer above, even though it wasn't me who asked the question.

I have a similar problem with a Studio XPS 1340. I finally read your solution after coming to the conclusion that my middle headphone jack was faulty. The jack always says it is connected to a headphone plug even when it isn't; hence, my internal speakers never work in Windows (though they did work in the preboot Dell Diagnostic test). There's even a slightly different "feel" between the working headphone jack on the left, and the faulty one in the middle. The middle one no longer "grips" the plug as well as it should; plugs have a tendency to slip out.

But despite a "gentle wiggle", I cannot fix the sense pin. Are there any other solutions besides sending the laptop back to Dell? It is under warranty, but shipping it back will no doubt take a while.

The gentle wiggle is more of a diagnostic tool than a solution. If it brings back audio then that confirms that the problem is in the jack. In your case I don't know of anything else you can do except get Dell to fix it if you need that jack to work.

Your model might have a jack daughter board, which is somewhat possible for a user to replace. It would involve a good amount of dismantling of the computer. I looked through the service manual and saw a reference to a daughter board cable which might mean that there is a jack daughter board but could not find an explicit reference to it.