[SOLVED] Headset mic works when plugged into cell phone, but not when plugged in to PC ?

[TBloop]

I bought a used Sennheiser PC 320 headset which has separate 3.5mm plugs for speakers and mic. I have had like 10 pairs of this headset which have worked perfectly when plugged into my PC.

The mic didnt work on these and I thought it was dead until I tried plugging it into my phone's headphone jack, and it does record audio just fine. I don't get it.

• I've tried wiggling the cables in every direction and it doesn't appear to be that. A physical inspection of the cable looks perfect. It always works perfectly on my phone but not on PC.
• I also am 99.9% sure my audio configuration is just fine - I can swap the headset with another of the same model and it works fine. I know I have the proper input device selected.
• I also tried plugging the headset into a USB soundcard I have (pic), and it still doesn't work.
• I also tried plugging the mic into an adapter (photo) to convert the dual jacks into a combined headset jack, and plugged that into my pink mic jack, but that didnt work either.

Very confused as to why it would work in my phone. Perhaps a physical issue to do with the plug's electrical layout? I know phones use a combined speaker+mic jack, while my PC uses separate speaker/mic 3.5mm jacks.

Here is a photo of the plugs, and another headset with the same plugs that works fine on my PC.

Please help!

 

[Ralston18]

Make and model phone?

The plugs may look identical but there may be some "internal" difference with respect to TS, TRS, TRRS (Tip, Ring Sleeve).

FYI:

https://www.cablechick.com.au/blog/understanding-trrs-and-audio-jacks/

Could be that someone "repaired" the used Sennheiser PC 320 headsets. Or the headset was problematic to begin with. Or possibly even fake.

 

[TBloop]

So... this is embarrassing. Someone else suggested something to me and as soon as they said it, I facepalmed because I realized they were most likely right.. and they were.

When I plugged it into my phone, I heard audio just fine and had the headset's mic close to my mouth while using the phone's recording app. It was the phone's internal microphones that were picking up my voice, not the headset. I can't believe I didn't pick up on that. I think it was the fact that I heard audio from the headset, so it just seemed like it was working. Also, the phone's microphones are very sensitive and impressive, (Pixel 4a 5G) so it didn't sound very far away.

In reality, the headset's microphone was busted from the beginning. I took it apart and found a tiny wire broken off.

Thank you for your reply, and also it appears you re-formatted by post to be more readable, which I appreciate.

I knew this was too strange of an issue.. mystery solved!

 

[Ralston18]

You are welcome.

(PS: I cannot take credit for the reformatting. That was already done.)