I am having a problem with the input ports in my computer (dell). I have spent the entire day trying to find a solution, nearly 90% of the forums that I read only talk about displaying disconnected/disabled devices or updating drivers. I have already updated/re-installed every kind of driver, i have been through every single possible hidden UI route to set the sounds configurations, so I guess my problem is either extremely utter-basic or some deep unaivoidable bug ... 

It all started when I tried to use the mic input port in my new computer (by the first time, i.e., same default configs of a brand new one). The device is not a mic itself, but the connector is the same (I guess). It didnt work, and (unless I unlikely burnt some chips) I assumed the problem was lack of windows 8.1 support and didnt bother to go further.

A few weeks later, I tried to use a webcam with inner mic. The connection is made trough a USB port. The webcam works good, but the mic doesnt. I have tested the web (and also the old device from before) in a laptop with windows 8, and they worked fine.

In the sounds configurations, the speakers devices are OK. The problem lies with the input devices. If I disconnect/connect them, the devices are recognized and listed accordingly. The stereo mixer is also always present. However, the stereo mixer can not be enabled, no matter how many ways I try to do that. The mic inputs are automatically set to enabled devices, however none of them really works. all the inputs (and the mixer) has no volume bar. If I try to change the configurations directly, the volume bar always locks to zero.

amongst the many complex solutions I have found, i runned this (sfc /scannow) and fixed manually a problem using the (DISM /Online /Cleanup-Image /RestoreHealth) command. I dont think this is related, because nothing changed. 

So, is there any other suggestion, besides turning on the visibility of disabled devices? I dont know if this is a problem of the SO or the machine itself..

Hi,

Have you try to change another mic that worked fine in another computer to see if it's the mic itself issue.

If the issue persists, it most probably the mic port issue.

Please open the device manager to see if that port is work fine.

Alternative, send your computer to repair center to do a hardware test.

Hi,

yes, I eventually tried other mics as well and the problem persists. I think it is a hardware problem. The stereo mixer is listed as a available input device, but it can not be activated. I reinstalled all sorts of drivers, tried every trick, messed up with the bios, but got nothing...

when I open the audacity, it gives an "internal portAudio error" message. in the device manager, everything seems fine. Although there are two HD audio devices (realtek and nvidia), i dont think they are interfering with each other. I disabled each one separately, but nothing changed. 

Under the system device category, there are two generic "HD audio controler" entries, but i dont think this is a problem...

under the USB category, every port is correctly working.

I have run across many other forums, and there are a lot of people with the same problem but no solution. I am currently waiting the visit of a tech support, who will eventually format the pc *sighs* and finally take the computer away to bring me a new one.

anyway, thanks for your help.