Apple MacBook Pro 13 2020 Intel silicone 820-01949-A A2251 no sound

[koinoyokan]

Hi guys, I hope you can help me. I'm trying to identify an audio chip on this device, since NVRAM reset, SMC reset and replacing speakers yield no results, I'm pretty sure it's the chip. The sound comes back briefly after sudo killall coreaudiod but it's muffled, as if the speakers are blown, which they are not. Same effect with SMC reset -- the sound comes back briefly, sometimes the chime can be heard, sometimes it's absent.

I have a schematic for the Open Board View, but I can't seem to locate what is usually an audio - U6200 or U6201, what am I doing wrong?

[mon2]

Is the audio codec listed in the System Report?

[koinoyokan]

Is the audio codec listed in the System Report?

You mean this?

[koinoyokan]

Forgot to mention -- the sound is present in the 3.5mm headphones, no distortions.

[mon2]

Appears to be that your speakers are the suspects and should be replaced. What is the history? Was this unit purchased new or used? Someone may have cranked the volume too high at some point and shredded the speakers? PS: Have any good remixed Isaan instrumental (upbeat) music? There was a tuk-tuk in Bangkok that was blasting some great music. Should have purchased it from him then. The replacement speakers should not be too expensive on Aliexpress stores - their CNY is over now.

[koinoyokan]

Thank you! Yeah, I'm waiting for a new set of speakers. It was bought new, it's my machine, I'm not an electrical engineer, but have fixed many laptops and phones for myself, friends etc. so I have some experience. I'll try replacing speakers, but just out of curiousity, what's the audio chip called on these?

[mon2]

It is odd for a new unit to have this behaviour. You should have a factory warranty. Suggest to take it to your local Apple Store. If you are in Bangkok, there is an Apple megastore outside of Central World plaza. Can post a short video of the place if you are interested.

These are called audio codecs.

[mon2]

As a FYI, attaching a short video of the Apple Store in BKK.

[koinoyokan]

Thank you, appreciate it. What I meant is, I bought it new, it's not new anymore I'll swap the speakers, will update this thread.

[koinoyokan]

All right it took me a while but reporting back.
I've swapped the speakers, the issue persists.

The weird thing is -- until the OS is fully loaded, the sound is present (chime, charging sound etc.) but once the OS is loaded, it disappears and is only present in 3.5mm headphones.

What could this be?

[mon2]

Boot from an external media (USB / external SSD / internet) and test again using a fresh loaded OS.

[koinoyokan]

Thank you for such a fast reply! I'm not entirely sure though how do you mean. You mean reinstall OS?

[dinhsbin]

I have the same problem with this model. Replacing the audio jack codec (u6300) didn't change anything.

[koinoyokan]

I have the same problem with this model. Replacing the audio jack codec (u6300) didn't change anything.

yeah, I'm still dealing with the same thing, I started using headphones until I have headspace to tinker with the audio chip or something, because no amount of reinstalling anything helped.
The audio returns sometimes before I log in, but it's muffled as if the speaker is blown, which is not true since I'd replaced them.

please share if you happen to find the culprit before I do.

[sajidmirza]

Change the audio jack and check.

[koinoyokan]

Will do, thanks sajidmirza

[dinhsbin]

Changing the audio jack made no difference. Exact same issue as OP. This must be a firmware issue because mine makes the startup chime Everytime and the sound is perfect. Not muffled.

[koinoyokan]

I also get the chime and 'power connected' sound sometimes, and it's not muffled as well.