Solved! Microphone broken after screen repair (fix or portable USB alternative)

Dec 18, 2020
I tinkered with the screen of my Thinkpad 540E to fix a broken column of pixels. A few weeks later, I noticed that the internal microphone is no longer picking up any sound. I have tried on both the preinstalled Windows 8 and my Ubuntu 16.04 systems. It was working on both before. The internal webcam that is part of the same module (see picture below) is still working. I am now considering two options:

1. Find and repair the problem.

2. Find a portable external microphone.

For option 1, I assume the problem is either with the cable or the webcam/mic module. How would I find out which is the problem? If it is the module, I would try to find a replacement. Replacing the cable requires so much disassembly, that I think the risk of damaging other parts is not worth it (see maintenance manual below).

For option 2, I would be looking for a USB replacement for the internal microphone, that takes minimal space, ideally about the size and shape of a wireless mouse dongle. It doesn't have to have high sound quality. Mostly, I would like to have it attached most of the time, but not worry about it when moving the laptop around. Does such a product exist? (The audio jack is combined for mic and headphones, so I assume attaching only a microphone, but using the internal speakers is not an option. Or am I wrong?)

My main use case is (spontaneously) allowing someone in the same room to take part in a Skype call. (Headset plugged in: person in the room cannot hear; headset not plugged in: people on the other end cannot hear.)

I am thankful for any replies to the above questions or alternative suggestions for my use case.

External links:
Webcam/mic module:

Maintenance manual:
Only way to see if it's the module or wire is to replace one and see if the issue is fixed. Since you were working on the screen you would be the only one to know the likelihood or one vs the other based on where you were poking around in.

I don't know of any external mic that can sit on a laptop without getting knocked of or broken off, unless it's not put in a bag.

Something like this Sony maybe and a bit of velcro/command strip

Or a lavalier mic and clip it to the screen bezel or somewhere

You should be able to use the audio options to set the speakers to the laptop speakers manually if needed.
Dec 18, 2020
Thank you for your reply.

I am leaning towards the cable being the problem, just because it has more area of potential damages; maybe I bent it when removing the frame. I was thinking of trying to use an ohmmeter to check the conductivity of the wire. I don't have mine on hand now, so I am not sure if the diodes are even small enough to catch the single contacts of the connectors on both ends. More importantly, is it safe to use an ohmmeter on delicate circuits like that?

I don't mind removing the mic when I am carrying the laptop in a bag. I was thinking of moving around in the same room (or to the next room), without having a cable hanging off the side that gets caught on things. So I was hoping to find something that is really just a microphone affixed to a USB plug.
In that way, your second suggestion would be ideal, if it could work just attached to the audio jack without the cable. However, I assume this will not work on a combi-jack, without a splitter. Is that correct? (That problem is what made me think of USB solutions in the first place.)

For example, with a headset attached to the combi-jack, the sound settings on Ubuntu do not allow me to switch to internal speakers. Is it possible the sound card or driver switches automatically? I will check this on Windows and maybe in other configuration tools on Ubuntu later.
Dec 18, 2020
I see. I guess a USB mic has to be bigger to include components to do the job of the sound card. Thanks.

I have now managed to move output to the speakers while a headset is attached to the combi jack. (On Ubuntu this works through the pavucontrol GUI and can be automate with the pacmd command, see here.)

Unfortunately, an external mic is recognised as headphones on the combi-jack on Ubuntu and I have not found a way to change that yet.

As I see it, the initial hardware question is answered, with the information that a mic can work without a splitter and a number of good mic suggestions. Thank you, hang-the-9.

Getting a mic recognised on a combi-jack seems to be an Ubuntu/Linux-specific question, that is better suited in other places, so for now I will mark this thread as solved.

I will post here, if I solve that part, but for now the headset solution works well enough for me, so I will not put too much energy into that. If someone finding this is looking for that part of information, the stackexchange link above and HDAJackRetast might be good starting points.

Update: The same problems exist on Windows 8: There is no straightforward way to use a headset mic and the internal speakers. A mic in the combi jack is recognised as headphones and there is no straightforward way to change it. For Realtek devices, there is Realtek Audio Manager that may solve some of these problems, but my card is a Conexant.
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