mtesgerous

Check the status of your sound card in Device Manager to see whether the driver was well installed or not. This can be easily fixed by re-install the sound card driver.

well, this is most probably hardware issue, better to get it to a local workshop for fix. BTW, what your device model?

You can remove the passcode by restoring your device from iTunes or Find My iPhone if you've turned it on before. The catch here is that you will lose your data by following the above method, so you should be aware of that. If you don't want any data loss, then you should first enter into DFU mode and use apps to get the passcode and paste the code somewhere, then exit DFU mode and input the passcode you just received. This method was recommended by a friend of a local workshop. More details can be found here, and you can leave comments for further requests.

Besides con's suggestion, you can also restore your phone from backup by using iTunes.

I have the same problem with you a couple weeks ago and got my screen replaced by Apple because it was a hardware problem.

What your device though? Form my udnerstanding, this mostly due to hardware failure. P.S. should give more details as more as possible to help you out by others.