Inspiron 17 5748 does not recognize external microphone

Hi,

Since posting the above, I have tried installing the Windows native audio drivers as suggested in another post, deleting the Realtek drivers as I went.  After three iterations, I finally had the Windows native drivers installed, but had the same issue with the headset microphone.  A few hours later, I discovered that the system had updated itself to Realtek drivers again.  I tried the mic again, but had the same problem.

Any suggestions would be GREATLY appreciated.  Growing problems with my hands make it painful to type any period of time, and I am trying to implement speech recognition so I can dictate longer documents and emails.

Many thanks,

Charlie

That suggestion was incorrect, because the Windows native driver doers not support the external mic jack.

Now that I think about it again, the Windows native driver in Windows versions prior to Win10 did not support the jack. Win10 changed the way Windows handles the audio, and might have included that feature in the Win10 native audio driver. I don't have Win10 so cannot test it one way or the other, so it might be a while before I am able to find out.

it is a single combination jack)

I checked the laptop documentation, and it says you can plug in just a headset, just a microphone, or a combination, so I tried an older headset I had that contained two plugs, one for the headphones and one for the microphones.  The headphones work fine, but the microphone is ignored.

Hello Charlie. The traditional headset with a separate plug for the headphones and a different plug for the mic will not work in a combo jack, because the mic plug is a TRS (tip/ring/sleeve) and the jack has to have the TRRS (tip/ring/ring/sleeve) type found on smart phone headsets. The headphone's TRS plug is fine to use in a combo jack.

I wonder which document said that you can use "just a microphone" with an Inspiron 5748 combo port? It might be difficult to find a stand-alone mic with a TRRS plug.

If I go to Sound, Recording Devices, the only microphone listed is Realtek High Definition Audio, regardless of whether or not I plug in the headset.

That is normal for Realtek. In Realtek, "Microphone" means the internal mic, unless an external mic is detected in the jack, then it means the external mic jack. That is similar to how the Playback devices are listed. Realtek just lists "Speakers", meaning internal speakers, unless external speakers or headphones are detected in the jack.

I have found some internet comments for similar problems indicating that an "IDT High Definition Audio Codec" should appear on the above list, but I don't know if that is for a specific, alternative audio board and whether it would apply in my case.

The names that appear in the list of devices are derived from the audio drivers for the devices. Earlier models of Dell laptops had IDT audio on the motherboard and used IDT audio drivers. Now most Dell laptops have Realtek hardware and use Realtek audio drivers, which is the case with your laptop. It would be inappropriate and probably impossible to install an IDT audio driver into your laptop, so IDT High Definition Audio Codec will never appear in the list of devices.

["Codec" usually means certain software, but in this context it means the audio hardware on the motherboard. When the Realtek driver is installed, it is called "Realtek High Definition Audio", and when the Windows native driver is installed it is called "High Definition Audio", but both names refer to the same hardware.]

In your next post you said "I have tried installing the Windows native audio drivers as suggested in another post."

That suggestion was incorrect, because the Windows native driver doers not support the external mic jack. It has to be a Realtek driver for the mic jack to work.

I tried the headset (a Logitech h151 with a 3.5 mm plug and four contacts)

That is the right type of headset you need to get the mic function of the combo jack to work, although I don't know anything about that specific headset. It could be that the jack is defective. Or it could be a buggy Realtek driver.  It could be that the impedance of the mic is different enough from what the jack sensor is set for by the driver, that it fails to sense the mic. Sorry but it is hard to pin down. You could contact tech support if you want to let them take a stab at it. -- if the laptop is under warranty.

You could get a cheap usb jack like this from Amazon or elsewhere, and use your traditional 2 plug headset with it.

                                              

Here is another thing you could try on the software side of things. Go back to Sound>Recording tab.  Right click on "Microphone". Click on Properties.

Click the Advanced tab and uncheck the "Exclusive Mode" box if it is checked. Test the headset mic. There is a small chance that this will help, but probably not.

Oddly, the laptop had the same problems with the Logitech h540 headset, which is a USB headset.

A usb audio device is a separate audio system from the integrated Realtek audio, because it does not use the Realtek codec. It has its own DAC and ADC, which are controlled by the Windows usb audio driver, which is part of Windows and not a separate download. When you plug in a usb headset, the system might not automatically switch to it. If you still have it, plug it in and go to the Recording devices tab. There should be a new listing for a usb device. Make it the default recording device. If it does not appear in the list of devices then it is probably defective, or something wrong with the usb port. Also make sure that the recording program you are using to test the mics is set to use the usb mic.

If you still have it, plug it in and go to the Recording devices tab. There should be a new listing for a usb device. Make it the default recording device. If it does not appear in the list of devices then it is probably defective, or something wrong with the usb port. Also make sure that the recording program you are using to test the mics is set to use the usb mic.

Hi, Jim,

I no longer have the headset, since Logitech said it was "defective", but I have ordered a Plantronics USB headset with good reviews and will try your recommendations above once I receive it.  I am increasingly convinced that the computer headset jack is faulty or the h151 has too high an impedance to be detected.

Thanks again for all your help...

Best regards,

Charlie

I received the Plantronics Audio 478 USB headset that I ordered today.  I plugged it in, and I was up and running in 30 seconds.  The microphone even worked!  So my microphone woes are finally resolved.

Best regards,

Charlie