Help! Intermittently no sound post-new upper case & I/O port

[Jules242]

Hi everyone!

I have a nasty issue after doing the following swaps on my A1466 2014 Macbook Air 13"

— new (used) I/O port to replace a headphone jack that got jammed up somehow
— new (used) upper case as a replacement for the keyboard, which for a while had non operational 1-9 number keys.
— new battery (just because)

I made the changes by following an iFixit guide for the upper case replacement and was as careful as I could be.

Everything worked ok at first, except for the sound. The sound devices (audio output/input) were not recognized in the audio settings pane. They just didn't appear. Furthermore, on a test google hangouts call, music I was playing was going through as if it was my microphone audio!!! I still don't get what happened. I re-opened the computer and saw that the mic cable wasn't as thoroughly in as it could have been. I adjusted. After boot the audio worked, as did the mic.

However, it'll work and then not work. I can't tell what changes, other than me opening and closing the mac. Is it possible that a cable is being tensioned with the hinge opening and closing? Could me not using gloves have gotten some oils on the logic board?

Does this sound to you like a cable issue or perhaps a logic board or I/O cable issue?

Thank you for any advice, community! I miss my audio already.

 

[Audit13]

Is it possible the replacement charging board is defective?

 

[Ruggy]

It definitely sounds like a loose cable issue and opening and closing the mac is exactly the sort of thing that will cause it to make contact or not.
Yes, maybe it is tensioned and it needs to be re-routed or maybe the cable itself has been very slightly damaged internally so check for that.
You know, if there are any kinks in it when you run your fingers over it, and whether there is a bit thinner somewhere…

 

[Jules242]

Is it possible the replacement charging board is defective?

It is possible. I just wonder why it would go back and forth between working and not working! I'm going to keep that in mind in case further troubleshooting fails.

It definitely sounds like a loose cable issue and opening and closing the mac is exactly the sort of thing that will cause it to make contact or not.
Yes, maybe it is tensioned and it needs to be re-routed or maybe the cable itself has been very slightly damaged internally so check for that.
You know, if there are any kinks in it when you run your fingers over it, and whether there is a bit thinner somewhere…

I see what you mean. Do you have any clue if a single mic or speaker cable that's not fully connected could do something as total as making the sound card unrecognizable to the system? (versus the speaker in question or the microphone not working).

Thank you both for your thoughts on this!

 

[Jules242]

Update: I disconnected and reconnected the speaker / mic cables and I think that did the trick! Something wasn't quite right. Thanks again for your advice