[Inspiron E1705/9400] [SigmaTel] No audio, headphones works

Simon,

The Dell laptops like yours with a Sigmatel 92xx audio chip 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 I think that it can be the cause of failure to trigger the software switching.

Normally the audio test in Dell Diagnostics would confirm that there is a hardware problem, but the Universal Jacks can cause a false positive 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 procedure might be to try a new motherboard. In other words, it can be tough to diagnose.

I would contact Dell about a repair if you are still under warranty.

Jim
 

Jim (or other people from dellcommunity.com),

Unfortunately I cannot call to the Dell support, because I bought this notebook from someone, who was not registered user. It is difficult for me to find the registered user of the notebook. People have not to help me in phone Dell service before I register myself. But I cannot :(

A little wiggle is working correctly I think - I saw this pin, inside. Is it possible to not work when mechanics and software is correctly and diagnostic give positive results?

However thank you for response.

Simon 

I have to say that I'm disappointed.  I have an Inspiron 6000 and bought a friends with a bad monitor because I found this audio port problem myself and noticed the port was faulty.  Well, his MOBO has the same problem and from what I've read this is a COMMON problem...One that certainly would warrant a recall.  My question is, since we have to deal with it.  Is there any way to solder, or shove an oversized jack in there, or a way to "trick" the S/W?  I can definately put a plug in and wedge it at a certain angle to get sound, so, it seems like this is possible...

jimco:

The cure for this problem is to replace the motherboard which can cost over $500, so you will probably have to just use headphones or external speakers. 

 

http://accessories.us.dell.com/sna/products/Motherboards/productdetail.aspx?c=us&l=en&s=dhs&cs=19&sku=WX413&mfgpid=167671&chassisid=8448

I9400 system board currently sells for $290

I know it's a MOBO problem as I've pulled them both apart and the audio port is on the MOBO, however this, it seems is likely to fail again.  Seems like you could short them out somehow.  I can get sound from the speakers if I put a plug in and push straight down firmly...