headset microphone issue with inspiron 3147

I'm using a TRR input jack that is connected to the headset with an extender that has a TR input.

Hello. I'm sort of scratching my head over that description. The laptop's combo port is designed for headsets with a TRRS plug. The combo ports do not work well with an adapter cable if that is what you are using. I think the adapter cables throw off the impedance sensing of the combo port, but I'm not sure.

Thanks.  Last night I tried jacking in a newer headset using the USB port and the computer found it immediately.  So clearly it has something to do with these particular headsets and the way they are being jacked in, which are older.  They have 2.5mm jacks but my computer requires 3.5 mm input.  So I used an adaptor.  I'm new to this so didn't notice that the 2.5 were of the 2-ring variety, while the male 3.5 mm was 3-ring.  I think that has something to do with it, but not sure what.

So I used an adaptor.  I'm new to this so didn't notice that the 2.5 were of the 2-ring variety, while the male 3.5 mm was 3-ring.  I think that has something to do with it, but not sure what.

Take a look at section 6 of the Headphone Jack FAQ to get an idea of the type of plugs required.

1. The 1st picture is of a plug with 4 metal segments divided by 3 black bands. That is a TRRS plug. (The 4 segments are the tip/ring/ring/sleeve.)

2. The 2nd picture shows a TRS plug (tip/ring/sleeve), which is a typical stereo plug.

The combo port on the laptop (the jack socket) can use a 3.5mm TRS plug for headphones, but if you plug in a headset with a TRS plug the mic part of the headset will not work.

The combo jack accepts a 3.5mm TRRS plug from a headset and with that type of plug the mic part of the headset will work, assuming nothing else is wrong. The extra segment of the TRRS plug is for the mic. (One segment is the ground, one is the mic, and the other two are for the 2 channels of the stereo headphones.)

I can't say whether or not you can make a 2.5 mm plug with an adapter work in a combo jack, but the mic of the headset will definitely not work unless the plug is a TRRS plug. Even then it might not work because the adapter might interfere with the impedance. Notice in the FAQ there is a picture of an adapter. Many people have reported that that adapter does not work and I think the failure is cause by impedance (the laptop's jack uses impedance sensing to determine when a mic has been plugged in).

Last night I tried jacking in a newer headset using the USB port

Usb audio is a completely different audio system from the Realtek audio system that is integrated on the motherboard, so you can't draw any conclusions about one of the systems based on the behavior of the other one. But you are right that the problem is lack of compatibility between the headsets' plugs and the laptop's jack socket.

Thanks for all the info and for taking the time.  I should be able to take it from here. Thanks again.