Wierd audio Studio 1557

Try running the audio tests in Dell Diagnostics. These interactive audio tests are designed to narrow down the problem to either the software or hardware. The tests are independent of Windows and drivers, meaning it doesn't matter if those are working correctly or not. To run Dell Diagnostics

1. Restart the computer and tap the f12 key as soon as it starts to boot up .
2. Select 'Diagnostic' from the boot menu. The computer will run its pre-boot assessment tests (PSA) before Dell Diagnostics starts. During the PSA you will hear some tones through the system speaker but this does not adequately test the audio hardware. Dell Diagnostics plays an instrumental piece of music complete with drums, so if you only hear some tones then you have only run the PSA.
3. Dell Diagnostics should open after the PSA tests, or you should see an option to open it. If you have ever reformatted your entire hard drive then Dell Diagnostics will no longer be there as an option. In that case run it from the Drivers and Utilities (Resource) CD if you have one.
4. Select 'Custom', then the audio tests. 

Press on the plug during the tests. If you get the same symptoms while the tests are running then you have a hardware problem that Dell will fix. If the problem is not present during the test then it is caused by a software problem. The tests do not have a vocal component soyou might not be able to make a positive judgement from the tests but it is worth a try.

If it is a hardware problem then the area with the jacks has to be replaced. On some models that means the entire motherboard but some models have a separate jack daughterboard and that is all that would need to be replaced.

Thanks, I'll do that.

This is obviously covered under warranty, right?

I've already had to replace the motherboard once due to a separate problem, now this.

That will be 3 motherboards in as many months on a 1k computer....